Tessa

Tessa is a Reaper. She is the Reaper that came for Dean's soul when he was put into a comatose state after the car crash he had with Sam and his father in Devil's Trap. She later teamed up with Sam and Dean in Death Takes A Holiday to stop Alastair from breaking one of the 66 Seals when he begun killing Reapers in a small town where no one was dying. She later helps Dean become Death himself in Appointment In Samarra as part of a wager with the entity himself.

Season 2
During the episode "In My Time of Dying", Dean was a spirit while his body laid in a coma. As he watches his father looking at his comatose body, he sees Tessa in her true form wandering the halls of the hospital. He would later see her again when his body flatlines and she hovers over his body. Dean, as a spirit, grabs Tessa's arm, but he is thrown back as soon as he touches her. Tessa then leaves Dean's hospital room.

While roaming the halls trying to find and kill Tessa, he comes across her taking the appearance of a beautiful, young woman. Tessa pretends that, like Dean, she is a spirit and that she doesn't understand why everyone in the hospital can't hear her. They then go and see Tessa's "body" with "her mother" watching over her. Dean and Tessa talk out of body experiences and accepting fate. He comments on how Tessa is strangely calm about the fact she could be dying. Dean then hears commotion in the hospital and runs towards it telling Tessa to stay where she was. Dean figures out that a child is dying and then sees Tessa, in her true form, approaching the child. Dean tries to save the child, but it's too late and Tessa leaves after the child dies. He then realizes that the creature after him is a Reaper.

When Sam reads their Dad's journal on Reapers, after Dean uses a ouija board to tell him one was after Dean. The two discover that Reapers can alter human perception. Dean confronts Tessa, who is now wearing all black instead of the hospital clothes "her body" was wearing. Tessa admits that she isn't a woman dying from a surgery mistake, but in fact the the Reaper of the hospital. She explains that to him that her current form and seeing her body and her mother was all part of her power of making him see what she wanted him to see. She also said that she changed her form after seeing how scared Dean was after seeing her true form and so she could talk to him.

She refuses to give Dean what he wants, a chance to live again. She tries to convince him to let go saying that he wasn't the first soldier that she's taken and that the battle will go on without him and that he died and honorable death. After he refuses to go, Tessa tells him that she can't force him. She then tells him that regardless of whether or not he comes with her, he won't go back into his body. She tells him years will pass by and eventually he'll become insane and violent turning into the very thing he and his family hunt. Meanwhile, John Winchester is making a deal with the Yellow-Eyed Demon.

Tessa finally tells Dean that he has to now choose whether or not to come with her. When he asks her "Where to?", she tells him that she can't tell him that. Before Dean has a chance to answer, the lights begin to flicker. Tessa turns and sees black smoke coming out of a vent. She tries to resist, but eventually is possessed by the the Yellow-Eyed Demon. She turns around, with yellow eyes, and says "Today's your lucky day, kid" and puts her hand on Dean's forehead. Dean wakes up from his coma, perfectly healthy but he doesn't remember a thing about his time as a spirit and with Tessa.

Season 4
In "Death Takes a Holiday", the Winchesters go to a town where no one is dying. When they realize that the Reaper of the town was captured and that killing the Reaper would break one of the 66 Seals, Dean and Sam with the help of Pamela Barnes become ghosts through astral projection. When they find the young ghost of Cole Griffith, the last person to die in the town, he tells them how black smoke took the Reaper that was after him. During their conversation, the lights begin to flicker and Tessa appears on the staircase in Cole's house.

Upon seeing the Winchesters, Tessa immediately acknowledges Dean. Dean asks who she is for he has no memory of their last encounter. Tessa kisses him returning his memories of his time as a spirit after the car crash he had with his father and Sam. She explains that she's come to town to fix all the deaths that aren't happening but should and heads for Cole. The Winchesters tell her that she can't take Cole because he knows where the demons took the Reaper of the town and that she needs to leave before demons take her too. She shows no concern over the captured Reaper or the battle between angels and demons and states that she's there to do her job. Although she refuses to leave the town, she does agree to hold off reaping and says that when it's safe to do so again she'll come after Cole first.

While Sam talks to Cole, Tessa talks to Dean. She says life is funny bringing the two of them back together again since he was "the one that got away" which rarely happens to her. Dean confides in her saying that after their time together for that entire year he felt that something was missing inside of him. He then says after regaining his memories that it was her and that he wished that he had gone with her because of the loss of his father and Sam. He then begins to talk about the horrible things he did in Hell and how he feels about being given a second chance, but is interrupted by the arrival of Sam and Cole. Cole tells them that he saw the black smoke at the town's funeral home. The lights in the house begin to flicker, then the front door of Cole's house swings open with black smoke coming in. It surrounds the four of them, but it leaves with Tessa.

After learning how to control their ghost powers from Cole, the Winchesters find Tessa unconscious with the other Reaper both laying in a sigil. The Winchesters try to free them, but are trapped and kept away from the Reapers when the demons use an iron chain. Alastair shows up and tells him that it takes the death of two reapers to break the seal. He performs a chant and then kills the first Reaper. Sam and Dean manage to save Tessa by using the telekinesis to make the ceiling chandelier fall on the seal trapping Tessa. With the seal broken, Tessa teleports away from Alastair and frees the Winchesters. All three of them then teleport out of the funeral home. Tessa and Dean reappear together somewhere in the town, Dean tells her to go while he searches for Sam.

After Alastair is captured and Castiel and Dean talk, Tessa appears before Dean and says that she could use his help. They appear before Cole so she can take where he belongs. She tells Cole that his mother will be miserable as long as he's around and she can still feel him and not let him go. Dean helps out by convincing Cole that someday when his family is gone he will be alone and he needs to go where he belongs. Cole willingly leaves and embraces Tessa in a hug, which causes him to be absorbed by her. Dean tells Tessa to look out for the boy to which she responds that he should look out for himself. Tessa tells Dean to stop lying to himself and questions him on calling his resurrection a "second chance". She tells him that deep down he knows that the angels have something bad in store for him and that there is no such thing as miracles. When Dean asks her about what she means, she disappears.

Season 6
In "Appointment In Samarra", Dean arranges for himself to have an out of body experience and then summons Tessa. She arrives, shocked by what he has done. Dean tells her he needs to talk to Death, but she refuses to summon him. However, Death comes on his own and makes a deal with Dean: He will get Sam's soul back, if Dean acts as Death for 24 hours. Dean agrees, puts on Death's ring, and becomes Death. Tessa is assigned to escort Dean around for the day. Dean has to kill the people on Tessa's list by touching them, and Tessa will reap the souls. Tessa tells Dean that the newly dead will often have questions.

The first person on the list is a robber who is shot by a clerk. Dean allows the man to suffer before killing him, but Tessa is not pleased and tells him to hurry up. Next, is a man eating pizza who has a heart attack. Dean touches him, and the man asks what it all meant. Dean responds with a quip, and Tessa tells the soul that Dean's new, and takes him on his way. Tessa then brings Dean to a hospital, and instructs him to kill a twelve year old girl with a heart condition. Dean refuses to do it, and so the girl miraculously heals, and the staff that were taking care of her are dismissed for the evening. Later, one of the nurses is brought in from a car wreck, and Dean must kill her. Tessa informs the nurse's spirit that she was meant to live for decades, and have children and grandchildren, but that Dean screwed up. Tessa takes the soul, and when she returns she tries to convince Dean to kill the little girl, insisting that tragedy will always follow her, and that more will die. Dean asks Tessa if she knew what would happen when he refused. She tells him she didn't, but that she knew Dean "knocked over a domino". Dean then decides to stop the husband of the nurse that died from dying in a car wreck of his own, and in doing so, takes of the ring and therefore loses his bet with Death. He returns to the hospital, and agrees to kill the little girl.

Season 9
In "Stairway To Heaven," Dean runs into Tessa. He grabs her and she's about to overpower him with super strength but he binds her with cuffs engraved with symbols of a reaper trap. When she won't cooperate, Dean was going to torture her with an angel blade but Hannah convinces him to approach it more civilly. She reveals that, as a reaper, she has been hearing the cries of the souls that are stuck and bound to Earth due to Metatron closing Heaven. She was deeply saddened by this and told Dean she eventually contemplated ending her own life with an angel blade but Castiel gave her something worth living for, toughing through Metatron's forces and reclaiming Heaven. She pulls the First Blade into her while Dean's holding it, killing herself.

Powers
Tessa has all the powers that a Reaper possesses:

Tessa
 * Flight/Levitation - In her true form, she has the ability to fly and/or levitate.
 * Invisibility - In her true form, Tessa is invisible to humans. She can only be visible to people who are about to die or the dead (Ghosts). Other beings such as Angels, Demons, and Death can see Tessa.
 * Intangibility - As a spiritual being, She is non-physical and can phase through solid objects, even people.
 * Alter Human Perception - She has displayed this ability the most. By this using this ability, she is able to change her appearance so instead of appearing before spirits in her true, more frightening form, she appears before them as a beautiful, young woman. But this ability also allows her to make people see what she wants to see. When she was trying to convince Dean that she was a spirit, she made him see "her mother" and "her body" in a hospital room.
 * Healing/Resurrection - When Azazel possessed her, he used this power to put Dean's soul back into his body. When he awoke all of his injuries were healed.
 * Teleportation - In "Death Takes a Holiday", she showed this ability it looks very similar to the way spirits/ghosts teleport.
 * Memory Manipulation - When Dean and Tessa met for the second time, he had no recollection of their time together. She was able to restore his memories of his time as a spirit after kissing him.
 * Telekinesis - She used this power to throw Dean back when he confronted her in My Time of Dying.
 * Reaping Powers- She can reap people only after they have died by Death's touch.