Gabriel

"Gabriel, okay? They call me Gabriel.[...] I skipped out of Heaven, had a face transplant, carved out my own little corner of the world...[...] I love my Father, my brothers—love them. But watching them turn on each other? Tear at each other's throats? I couldn't bear it, okay?! So I left."

- Gabriel to Sam and Dean in Changing Channels

Gabriel, also known as Loki or The Trickster, is the youngest of the four archangels created by God. Despite the fact that he is the youngest of the archangels seen on the show so far, he is still very powerful. Gabriel is very compassionate towards his family. Although he was the very first celestial to be seen on the show, he was the last archangel to be revealed. When his older brothers, Michael and Lucifer, turned on each other and began fighting one another, he couldn't bear it, retreating to Earth as an escape.

According to Gabriel, The Apocalypse was an issue he had to cope with on a daily basis. Gabriel loved both his father and brothers, but he was unable to choose sides between Michael and Lucifer, so he left Heaven and "skipped out" to Earth. He describes his experience at obtaining a vessel as having a "face transplant." After that, he went under "witness protection" and he began posing as a trickster, a Pagan god named Loki. Gabriel made quite a name for himself among other Pagan gods, and was in fact known as the famous Norse god, Loki. As Loki he killed people across the world that he deemed to be douchebags, though some he spared to spread the word, and eventually encountered Sam and Dean who foiled his plans on more than one occasion and discovered his true identity. Once Gabriel was exposed he eventually aided Sam and Dean in stopping the Apocalypse by telling them the secret of the Cage door, but along the way was "killed" by Lucifer. Though he reveals himself before Castiel in the plan to stop Metatron, it is unclear as to whether it is really him.

Early life
As the youngest archangel, Gabriel lived in Heaven with his father and siblings. Gabriel also mentioned that the Horn of Gabriel was, as he said, "One of Dad's little party favors that I never got around to messing with." In the fight against the Darkness, Gabriel helped his father and brothers win the war.

When God created humans and asked all angels to bow down before them, Gabriel did so whereas Lucifer rebelled. Gabriel also mentioned that what humans call the Apocalypse, he use to call Sunday Dinner. So having grown tired of watching his brothers fight each other in Heaven, he fled to Earth thousands of years prior to the series, assuming the role of a Pagan trickster. Gabriel loved both his father and brothers, but couldn't choose sides. He takes an unnamed vessel, embracing the lifestyle of a demi-god and meting out "just desserts" to those he felt deserved punishment. During his time on Earth he becomes a friend to some of the real Pagan gods he encounters, who know him as Loki.

Season 2
In Tall Tales, Gabriel, posing as a janitor, lets the Winchester brothers into the office of a university professor, who apparently was killed by the ghost of a female student he had had an affair with, and who had also killed herself after being dumped by the professor 30 years ago. Loki tells the brothers how he was the one who found the dead professor, as well as the fact that the professor wasn't alone but rather with a young girl. He explains that he told the police but they never found her. Gabriel then explains how the professor had a tendency to bring young girls to his office and have sex with them.

After a fraternity brother, who was a horrible pledge master, was probed by aliens and a research scientist, who tested on animals, was killed by an alligator in the sewer, Dean and Sam called Bobby for advice. After hearing about the personalities of the victims and hearing about the brothers' arguments (Sam blamed Dean for his lost laptop and Dean blamed Sam for letting the air out of the Impala's tires and potentially bending the rims), Bobby told them that they're dealing with a trickster.

Bobby explains that tricksters are immortal demi-gods that can create anything out of thin air and tend to play deadly pranks on the high and mighty. Bobby also mentions that tricksters need a diet high in sugar. Dean deduces that the janitor is the trickster, because they find candy wrappers in his locker. As they come up with this conclusion, Gabriel is seen reading a newspaper looking for more possible urban legends to bring to life.

The brothers, posing as electricians again, go to see Gabriel. Sam makes up an excuse to separate from Dean and Gabriel so he can search his locker and finds the newspaper filled with urban legends. Later, Gabriel spies on Dean and Sam arguing whether or not there is enough evidence to prove Gabriel is the trickster. While Sam leaves to search Gabriel's home to find more evidence, Dean stays behind to keep an eye on Gabriel. Eventually, Dean gets tired of waiting and decides to hunt Gabriel alone and eventually finds him in a lecture hall.

However, Gabriel was waiting for him and creates two beautiful women out of thin air as a peace offering for him. He explains to Dean that he's run into hunters before and that he knows that he and his brother are hunters. Dean tells him that he can't let him keep hurting people, to which Gabriel replies that the people he hurt got what they deserved. Gabriel continues by saying that he likes Dean and Sam and doesn't want to hurt them. He suggests that Dean is free to enjoy the women he's created as long as he wants while he moves on to the next town. When Dean declines, Gabriel says that's too bad and insists that Dean shouldn't have come alone. Dean assures him he didn't and both Sam and Bobby enter the lecture hall with blood-covered wooden stakes in hand.



Gabriel realizes that the fight Dean and Sam had before was staged and compliments them for tricking him. Gabriel then creates a chainsaw killer to fight Sam and Bobby while Dean is forced to fight the two beautiful women, who have now been granted super-human strength. When Gabriel's attention is drawn, Dean is able to stab him with a blood-covered wooden stake, destroying his creations and seemingly killing him. The Winchester brothers and Bobby quickly leave so no one sees them with Gabriel's corpse. After they're gone, Gabriel's corpse fades away. It is shown that what Dean stabbed was actually a duplicate and that the real Gabriel was very much alive.

Season 3
In Mystery Spot, Gabriel traps Sam in a seemingly infinite time loop, where Dean continually dies in increasingly strange ways (once by Sam's own hand), with Sam continually failing to save him. After a countless number of repeats, Sam eventually realizes that a trickster must be at work, and manages to locate the culprit. He threatens their tormentor with a blood covered stake, causing Gabriel to reveal himself, revealing that he survived their previous encounter, and agrees to break the loop. However, when Sam then considers killing him anyway, Gabriel supposedly stops the loop. This, however, proves to be false. Dean once again dies, but this time there is no loop to revive him. Throughout the next several months, Sam becomes a far colder and more calculating person as he attempts to track down Gabriel, killing whatever threat he can along the way.

Eventually, it is Gabriel who calls the younger Winchester to him, where he tries to drive in a point: that the two brothers continually sacrificing themselves for one another would bring no good, and when people die, they just have to learn to accept it and live with it. He says that "this is what it will be like without Dean." Nonetheless, Sam pleads with him to turn back time so that he can save Dean. Gabriel comments that it's like talking to a brick wall and snaps his fingers, reversing time to the Wednesday when Dean died for good.

Season 5
In Changing Channels, the brothers investigate the death of a man in Wellington, Ohio who apparently was killed by the Incredible Hulk. After the brothers learned that the man who died was well known for a having a bad temper and Sam found several candy wrappers at the crime scene, they deduce that the Trickster was responsible for the man's death. Realizing that the Trickster was one of the most powerful beings they ever met, Sam convinces Dean that they should ask for his help. Gabriel then sends a fake distress call to the brothers' police scanner to lure them to an abandoned warehouse.

When the brothers enter the warehouse, Gabriel transports them into Dr. Sexy M.D., a television show that Dean watches. After the brothers are confronted by the show's main character, Dr. Sexy, Dean was able to figure out that he was the Trickster in disguise due to the lack of cowboy boots, so Gabriel transforms back into his original form. Gabriel deduces that they came to ask for his help and clean up their mess.

Sam asks for him to just hear them out, to which Gabriel agrees, saying that if they survive "the game" for the next 24 hours then they can talk. Gabriel then teleports away, not answering Dean's question as to what the rules to the game are. Castiel attempts to get the brothers out of Gabriel's television world, but is teleported away from the Winchester brothers by Gabriel. The brothers eventually realize that "the game" is to play their roles.

Castiel manages to escape from Gabriel and teleports to the brothers again. Castiel then tells the brothers that the Trickster is much more powerful than it should be and that Loki may not actually be a trickster. Before he can continue, Gabriel telekinetically throws Castiel into a wall and teleports him away.

Dean then tells Gabriel that they get it and that "the game" is playing their roles. Gabriel corrects him and states that that's only half the game. He continues and says the other half is for the brothers to play their roles as the vessels of Michael and Lucifer. Sam tells Gabriel that if they say "Yes" then the world will end.

Gabriel responds saying that it's their fault and that they started the Apocalypse and there is no stopping it so they might as well get it over with. Dean asks Gabriel whose side he's on, Heaven or Hell. Gabriel answers that he's on neither side and that he doesn't side with Michael or Lucifer.

Dean doesn't believe him and tells him that he's a bitch for one of them. Gabriel becomes angered and pins him against the wall and tells him to never presume what he is. He then tells the brothers that they will accept the roles destiny has chosen for them or he will keep them in his television world forever.

Gabriel snaps his fingers and transports the brothers into a cop show. Dean stabs a man, who displayed traits of the Trickster, with a blood covered wooden stake. A cop then begins to laugh and reveals himself to be Gabriel in disguise telling Dean he got the wrong one. Dean asks him, "Did we?" as Sam surprises Gabriel by stabbing him from behind with a wooden stake. It seems that Gabriel was killed as the television world disappears and the brothers are back in the real world.

The next day, the Winchester brothers realize the Trickster is not dead and they are still in his television world since Sam is the Impala, complete with Nightrider lights. Driving along, they realize that Gabriel is not actually a Trickster and Dean is able to put together a few clues and realizes what he really is. Dean and Sam then yell out to Gabriel that they give up before Gabriel teleports to them. Dean refuses to say "Yes" until Sam is normal to which Gabriel complies and turns Sam human again with a snap of his fingers.

Then the brothers set fire to a circle of holy oil that Gabriel is standing in the middle of. Dean accuses Gabriel of being an angel due to the stake not working. Gabriel tries to deny this, but it's no use due to his inability to step outside of the circle so he teleports the three of them out of the television world.

Gabriel asks the brothers how they figured out. They explained what gave him away was how he easily overpowered Castiel and the way he talked about Michael and Lucifer, Dean saying that no one gets that angry unless they're talking about their family. Sam then asks who he really is. The brothers are surprised when he reveals his true identity as the Archangel Gabriel. Gabriel explains to the brothers that he left Heaven and went into "witness protection," becoming a trickster. He explains to Dean and Sam that he loves his brothers, but he couldn't take them fighting each other so he left. Sam then tells him to help them stop the Apocalypse, but Gabriel replies that it can't be stopped. He goes on saying that because of them he has to watch his brothers kill each other and he just wants the Apocalypse to be over with and couldn't care less whether Heaven or Hell wins. Gabriel continues saying that what humans call "The Apocalypse" was "Sunday Dinner" for him with his family and that the Apocalypse isn't about a war but about two brothers who loved each other and betrayed each other. He then states that the brothers should be able to relate. The brothers are confused by this statement so Gabriel explains Michael, like Dean, is "the big brother" who's "loyal to an absent father" and Lucifer, like Sam, is "the little brother" who's "rebellious to daddy's plan."

Gabriel asks the brothers if they ever wondered why he was so interested in them. He answers that it was because the brothers were born to be the vessels of Michael and Lucifer and that all the angels knew that they were going to fight and that one will kill the other. Dean says that that won't happen, but Gabriel apologizes and says it will. Dean tells Gabriel to bring Castiel back threatening to kill him by pouring holy oil on him and setting him on fire, to which Gabriel complies and brings Castiel back with a snap of his fingers. Castiel greets Gabriel revealing that he figured out his true identity. Gabriel greets his brother and sarcastically asks him how the search for Dad is going. The three begin to leave and Gabriel asks if they plan on leaving him trapped forever. Dean turns around and says no, explaining that they don't screw with people the way he does. Dean goes on and says the Apocalypse isn't about a ultimate match between his brothers or a destiny that can't be stopped, it's about him being too afraid to stand up to his family. Dean then hits the warehouse's fire alarm, activating the sprinkler system and extinguishing the burning Holy Oil. The three then leave Gabriel.

In Hammer of the Gods, Gabriel comes to save Dean and Sam after they are captured by a group of Pagan gods. Before Dean and Sam say his name, Gabriel uses his powers to take away their voices. The Norse god, Baldur, asks Gabriel, who he knows as the Norse god Loki, why he's here. Gabriel answers he's come to talk about the Apocalypse and how they can't stop it. Before he goes on, he teleports Dean and Sam back to their room telling them that the "adults" need to talk.

Shortly Gabriel joins the brothers, interrupting their planning on what to do about the situation. Dean immediately accuses Gabriel of being behind the predicament that he and Sam are in. Gabriel corrects him and states that he's here to save them. He explains that the Pagan gods are either going to use the brothers as bait or kill them. Dean notes how ironic it is that a couple of months before Gabriel was trying to force him and Sam to "play their roles." Gabriel replies saying that Michael and Lucifer are still going to fight, simply not tonight and not here. Dean then asks Gabriel why he cares. Gabriel reveals to the brothers that he and Kali, the Hindu goddess, had a "thing." Sam asks Gabriel if the Pagan gods have a chance against Lucifer, wondering if this was their best chance to kill Lucifer. Gabriel tells him that they stand no chance against him and that Lucifer's "gonna turn them into finger-paint". Gabriel then explains that he can't teleport the brothers out since Kali has their blood and performed a binding spell, which essentially puts them on a leash. However, Gabriel plans on seducing her and stealing their blood from Kali. Dean then tells Gabriel that they have to save the guests and employees that the Pagan gods plan on feeding on as sacrifices. But Gabriel tells Dean to forget them since it'll be hard enough to break he and Sam out. But Dean remembering that the other gods referred to him as Loki, threatens to expose Gabriel's true identity to them if he doesn't help the others. Gabriel, having no choice, reluctantly agrees.

Gabriel then teleports to Kali and attempts to retrieve the blood of the Winchester brothers. He tries to seduce Kali but he is quickly turned down by her. It is revealed that Kali was the one who invited him to the gathering of the Pagan gods, hoping that he would take the situation seriously. He tells Kali that he is taking this seriously and tells her that if she and the other Pagan gods fight they will die. Kali asks how he's such an expert. He tells her that he's tangled with angels before. He then begs her not to fight, but Kali says that she has to. Gabriel responds saying that he had to try and asks Kali if she still loves him. Kali says no, but then pulls him in to kiss him. As they kiss, Gabriel attempts to take the brothers' blood, but is interrupted when Kali scratches him and takes some of his blood. She reveals to him that she knows that he is the Archangel Gabriel and now that she has his blood he is bound to her forever.

Gabriel is then taken to the meeting room and soon joined by the captured Winchester brothers. Kali takes Gabriel's archangel blade and accuses of him of being a spy, but he corrects her and says that he is a "run-away." He then says that even though he lied about his identity, that doesn't mean he's wrong about them losing to Lucifer. He tells her and the other gods that he's "skipped ahead" and seen how this ends. Kali then lectures him about how arrogant angels are for thinking that they can just "rip the planet apart" and how his Father isn't the only god. She then says there are billions of pagan Deities and that they were here first and if anyone is going to destroy the world, it's her. Kali apologizes and then stabs Gabriel with his own blade, killing him.



After Dean makes a truce with the Pagan gods and escorts the captured employees and guests out of the hotel. In the parking lot Dean finds Gabriel is alive and well hiding in the backseat of the Impala. Gabriel tells him that the sword was a fake and that he made it from a can of Diet Orange Slice. Gabriel then tells Dean to grab their blood because Kali seems to like him meaning he can get close to her, then, once he does, he'll be able to teleport him and Sam out. Dean refuses and asks for Gabriel's real Archangel Blade then tells Gabriel that he should actually help them kill Lucifer. Gabriel asks Dean if he's serious, unable to believe that he would team up with a bunch of "monsters." Dean replies saying this is the best idea he has for taking out Lucifer. Gabriel sarcastically tells Dean good luck, that he's leaving, and that it's not his problem if the Pagan gods want to commit suicide. Dean tells Gabriel that he knows he's lying and that he does actually care about the Pagan gods like they were his actual family. Gabriel tells Dean that he can't kill his own brother to which Dean asks him, "Can't or won't?" before he leaves.

Later, after Lucifer has killed all the Pagan gods except Kali, Gabriel teleports next to the Winchester brothers, who are taking cover while Lucifer and Kali fight. Gabriel hands Dean a DVD telling him to guard it with his life. He then uses telekinesis to throw Lucifer into the hallway stopping him from killing Kali. He tells Dean and Sam to get Kali out of here, leaving him to take on Lucifer alone. Lucifer can't believe Gabriel is doing this over a girl, especially a disgusting Pagan goddess. Gabriel tells Lucifer that he is his brother and that he still loves him. But then he lectures Lucifer on how he can play victim all he wants, but they both know that "Dad" loved him best over Gabriel, Raphael and Michael. Gabriel goes on saying when God created humanity he couldn't handle it and he went on a temper tantrum and that now it was time for him to grow up. Lucifer believes that Gabriel is doing this for Michael, but Gabriel states that if Michael were here he would "shiv his ass too". Lucifer then insults him calling him disloyal, but Gabriel states that he is loyal, not to the Pagan gods but humanity. He then tells Lucifer that their Dad was right and that humans are better than angels, they may be flawed but they try to do better and forgive. Lucifer asks his brother to not make him kill him, but Gabriel tells Lucifer that no one makes them do anything. Gabriel tries to kill Lucifer by having him talk to a copy while the real Gabriel is behind Lucifer. Gabriel attempts to stab Lucifer with his archangel blade, but Lucifer turns around and stabs his brother with his own blade. The copy disappears and Lucifer calls it "amateur hocus-pocus" reminding his little brother that he learned all his tricks from him. Gabriel then dies with his older brother looking down on his corpse weeping softly.

Later, Dean and Sam view what Gabriel gave Dean before they left. It at first seems like a regular pornographic DVD, but then they see Gabriel is in the video. In the video, Gabriel explains that if the brothers are watching this that means that he died and failed to kill Lucifer. Gabriel goes on to say that he was their only shot at killing Lucifer, but the brothers can still trap him. He explains that the cage that they freed Lucifer from is still there and that can use it to imprison him again. Gabriel then explains that the cage has four keys and that not even Lucifer knows this, but the keys are the rings of the The Four Horsemen of the Apocalypse. Gabriel then tells Dean that he was right and that he was afraid to stand up to his brothers, but that's no longer the case. The brothers then stop the video and go on their way.

Season 9
In Meta Fiction, Gabriel, who was believed to be dead, makes his presence known to Castiel through Casa Erotica 14, eventually manifesting in his motel room, asking him for help against Metatron. When Cas asked how he was alive, Gabriel said, "You can't take the trick out of the Trickster." He said he was in and cast out of "the safest place in the universe -- Heaven." When they decide to stop at a Gas-N-Sip, a group of Metatron-loyalist quickly descend upon them. Before they can enter the gas station Gabriel tells Castiel that he still has some of his Archangel mojo left, and will hold them off so Cas can make his escape. However Castiel realizes that the whole thing is an illusion, by the fact that he had ripped his coat earlier, but in the Gas-N-Sip there was no hole. Gabriel pleads with Cas to hear Metatron out, that he is really trying to help him. However he isn't able to specify how, as he only skimmed through his parts of script. Before Gabriel leaves, Cas asks him if he's really dead, but only gets an eyebrow wiggle from Gabriel before he disappears. Metatron later comments on how well Gabriel, being the Trickster, played out his part.

Personality
Acting as a demi-god, Gabriel behaves in a mischievous manner enjoying toying with his victims, humans he believes should be brought down a notch. He embraces a hedonistic lifestyle, including the "sweet tooth" for which that type of demi-god was known. Even after revealing himself to be an Archangel, he still used misdirection to achieve his goals and to protect himself. He is often sarcastic. Gabriel's manner is the most human of any of the angels so far, perhaps because of his long sojourn on earth. He holds humans in high regard, despite their many faults, something the other Archangels did not, not even Michael.

Nothing is known of his vessel, though the Pagan gods' familiarity with it indicates Gabriel had possessed him for a long time, possibly centuries.

Powers & Abilities
Despite being the youngest Archangel created by God, Gabriel has nigh-omnipotent power, and is one of the most powerful beings in existence. He originally appeared to the Winchester brothers as a Trickster. Before they knew he was an Archangel, Sam called him "one of the most powerful creatures we've ever met." Both Castiel and Sam have said that Gabriel is much more powerful than a Trickster, too powerful to be one in fact. Despite this impressive power, Gabriel is still younger and weaker than Michael and Lucifer and possibly Raphael, but there is no evidence to substantiate this. He has been in the same vessel for at least three years, likely thousands of years owing to the Pagan Deities familiarity with this vessel, and has not yet begun to decay like Lucifer did, so it is assumed that he found his one and only 'true vessel'. As an archangel, Gabriel has nigh-omnipotent powers. All of the powers he has demonstrated on the show are listed below.


 * Immortality - Gabriel has an indefinitely long lifespan, and is unaffected by disease, toxins or time. He does not require food, water, oxygen, or sleep. His vessel has not aged, as evidenced in "Hammer of the Gods", when the pagan deities recognized his vessel as "Loki," who had presumably been around for millennia.
 * Angelic Possession - Gabriel requires a vessel while on Earth. He needs the vessel's consent. Bloodline requirements, if any, for Gabriel's vessels are unknown.
 * Invulnerability - Gabriel can not be killed by conventional weapons, however certain weapons (such as an Archangel Blade and Death's Scythe) can kill him. He can also be killed by God, Death and his elder brethren too.
 * Super Strength - Although the youngest archangel, Gabriel endows his vessel with dramatically increased superior strength and can exert tremendous amounts of physical force. He can overpower and kill any human, lesser angel, seraph, demon, monster, and spirit. When Dean confronted Gabriel by grabbing him against a wall, he almost broke Dean's arm with one hand, even though he was restraining himself. He overpowered and almost choked Dean unconscious on one occasion, still restraining himself. The only confirmed exceptions to his overwhelming strength were his Archangel brothers.
 * Shapeshifting - Gabriel can change his vessel's appearance at will.
 * Teleportation - Gabriel can travel from one place to another, instantaneously, without occupying the space in between and even take others with him.
 * Telepathy - Gabriel is able to read the thoughts and memories of humans and monsters.
 * Empathy - Gabriel is able to read the emotions of humans and monsters.
 * Advanced Telekinesis - Gabriel can impart kinetic energy on matter with his mind. Castiel, although being a powerful celestial, was no match for his much older "bro". Gabriel slammed him into walls, duct taped his mouth and played around with Cas like he was nothing using telekinesis. This further proved that the power of ordinary angels could not even compare with the immense powers of the four Archangels. He even managed to use his telekinesis to throw his older brother Lucifer across a room with considerable force, although Lucifer was caught off guard at the time and quickly recovered.
 * Cosmic Awareness - Gabriel possesses an immense amount of knowledge of the universe. He even possesses knowledge on his older brother's Cage, and how to open it.
 * Chronokinesis - Gabriel can travel forwards or backwards through time. He can also put others in time loops. He was able to send Sam back to the day Dean died "permanently" with just a snap of his fingers, apparently rewinding time to do so.
 * Reality Warping - Gabriel is remarkably talented with this power and can accomplish just about anything with it, making him virtually omnipotent, and it is his trademark as well as his most utilized ability. He can warp reality, whether it be by making objects or living beings appear out of thin air, or by reshaping objects into something else entirely, or by creating unreal dimensions, wormholes and large time loops. He also once turned Sam Winchester into the Impala. He easily fooled the most powerful of pagan gods, created a fake Archangel blade - which he said he created from a can of Diet Orange Slice - that Kali "killed" him with. None of them knew it was a trick and believed Gabriel was in fact, dead after Kali stabbed him. He was later killed by Lucifer, which everyone thought he died permanently this time. But then he returned after a very long time although details of his return are unknown he stated he was hiding in the safest place in the universe but was knocked out of Heaven by Metatron's spell. His amazing skill in reality warping was attributed to his elder brother Lucifer, as he taught Gabriel everything he knows.
 * Conjuration - Gabriel can create anything out of thin air, whether it be people, creatures, beings, or objects.
 * Self-Duplication - Gabriel can create another duplicate of himself to deceive others, as he did a few times with the Winchesters, once with a group Pagan Gods, and again with his older brother Lucifer.
 * Apporting - Gabriel was able to casually send Castiel away, and brought him back again just as easy. Gabriel also sent Sam and Dean back to their room with a snap of his fingers. Also, with a single snap of his fingers, he sent a small army of angels away which may have been an illusion.
 * Pyrokinesis - Gabriel was able to light two candles with just a thought.
 * Super senses - Gabriel was able to hear Sam and Dean "fighting" down below from a closed window many floors up, and on another occasion, while he was walking away from the restaurant, he heard that Sam had found him out and threw him back to Tuesday again.

Weaknesses
Although he is remarkably strong and very powerful, as a celestial being, Gabriel was still susceptible to the angelic weaknesses that even archangels possess.
 * Archangels - While lower classes of angels can't physically hurt Gabriel, with their own strength, archangels can hurt each other. Gabriel's closest and older brothers can harm him. Michael and Lucifer in particular are said to be much more powerful than him and likely could easily overpower if not kill him, and so can Raphael. Whilst Gabriel is also powerful enough to harm them as well, like he did with Lucifer, he was bested by Lucifer.
 * Holy fire - Gabriel can be trapped in a loop of holy fire, passing through the flames will destroy his vessel, however he wouldn't be killed.
 * Lucifer's Cage - This cell can hold any angel, therefore including Gabriel, without any internal means of escape.
 * Archangel blades - Archangel blades can harm and kill Gabriel.
 * Enochian Sigils - Gabriel cannot locate someone if they are warded by enochian sigils.
 * Jesse Turner - He could destroy the entire Host of Heaven with a word, including Gabriel.
 * Death - As literally the bringer of Death, he can kill any being, including Gabriel.
 * God - As the creator of Gabriel, and the most powerful being in existence, God can kill Gabriel
 * The Darkness - As a primordial force that predates God and Death, It can kill Gabriel.
 * Souls - When Castiel was empowered by 50,000 hell-bound souls, it was enough to hurt Raphael and the consumption of millions souls and Leviathan from Purgatory gave Castiel so much power that he could snap his fingers and obliterate Raphael. It is possible that it would work against Gabriel as well.
 * Heaven's Weapons - Lot's Salt could irreparably dissolve even Raphael's vessel, but didn't kill Raphael himself. All of Heaven's weapons acting together could possibly enough to cause Gabriel to flee for his life.
 * Blood spell - Kali controlled Gabriel with blood spell.
 * Leviathans - As Leviathans are said to predate and overpower even the Angels, the Leviathan can harm, and even kill Gabriel. They are also able to block him from using his angelic powers.
 * The First Blade - Being powered by the Mark of Cain and therefore The Darkness, the blade can kill Gabriel.
 * Death's Scythe - As the scythe was even able to kill Death, it can therefore kill Gabriel.

Appearances

 * Season 2
 * Tall Tales


 * Season 3
 * Mystery Spot


 * Season 5
 * Changing Channels 
 * Hammer of the Gods 


 * Season 8
 * The Great Escapist (mentioned by Metatron)


 * Season 9
 * Meta Fiction

Trivia

 * His aiding the Winchesters to stop the Apocalypse is ironic, since in Norse mythology Loki is the one responsible for starting Ragnarok, the Norse Apocalypse. Loki’s role is similar to Lucifer and it results in the death of most of the major Norse gods.
 * In popular culture, it is said that Gabriel shall blow the trumpet blast that initiates the end of time. (This is most likely taken from the Islamic religion as there is an archangel Israfel, who corresponds with Raphael, not Gabriel, which is said to signal judgment day). Ironically, Gabriel is the only archangel to help the Winchesters stop the Apocalypse. Perhaps he did it due to the main antagonists hastening the Apocalypse, and he felt that it wouldn't be right.
 * He is the only archangel to be featured in 4 seasons.
 * He is also the first Archangel to appear, although it wasn't revealed until Season 5.
 * Gabriel is the only archangel who has only used one vessel.
 * If Gabriel had really died, it is possible he was only resurrected by Metatron to be a part of his "story."
 * With Gabriel seemingly alive while Michael and Lucifer are sealed in Hell and Raphael dead, he is more than likely the most powerful celestial alive and free.