Rugaru

Rugarus are carnivorous humanoids which feed on 'long pig' (human flesh).

Characteristics
Rugarus are born and live as humans for all intents and purposes, typically being unaware of their condition, but at a certain age they will suddenly begin craving large quantities of food. This condition is not a virus; rather, it is passed down genetically. A person who possesses this gene will eventually give in to the urge to feed and will devour a human. The change starts out with an increased hunger for all food, but quickly transforms into a powerful craving for flesh, specifically human. The change itself is very fast, occurring within minutes of the Rugaru's first bite of human flesh. Once the Rugaru gives in to its desire to feed on a human, there is no going back; the Rugaru will lose its human appearance and change into a monster.

Although it is believed by some that a person with this gene can overcome their curse, no Rugarus are known to have been successful in this. Apparently, the final change can be avoided as long as the Rugaru resists eating human flesh. Unfortunately, the urge is extremely strong and is practically impossible to ignore.

Powers & Abilities

 * Hunger - Rugarus suffer with a unfightable need to feed on human flesh.
 * Super strength - Rugarus are stronger than humans and most other monsters, they can easily snap bones or break steel chains.
 * Super speed - The Rugaru's speed is a necessity, allowing it to stalk and catch its prey.
 * Super stamina - Rugarus never tire and don't give up on their prey, however they do require substance.
 * Invulnerability - Can't be killed by normal weapons. Fire is the only weapon that can harm them.
 * Super senses - Rugarus have incredible smell and sight, one was able to catch the pleasant odor of a young woman undressing from far away.

Weakness

 * Fire - Rugarus can only be killed by fire. The hunters need to burn them alive.

Behavior
After consuming human flesh, the Rugaru will act as a predator, often eating violently and moving on all fours. Their human, emotional side becomes less active, yet they retain all physical abilities. They do retain full memory of their human life and may display some capacity for emotion and empathy, but this is almost always eclipsed by their overpowering need to feed.

Appearance
Rugarus look nearly completely human, aside from several exceptions:

Their skin is "wormy" (as described by Travis); it is considerably paler than human skin and has prominent veins and skin folds. Full grown Rugarus obtain demonic, pitch black eyes, while unchanged Rugarus have red, bloody scleras.

Season Four
Sam and Dean learn of the existence of Rugarus when a fellow hunter named Travis asks for their help. He sends them to watch Jack Montgomery, a man who is about to become a Rugaru. Jack is showing signs of his impending change but has managed to resist it so far. When Sam and Dean later meet Jack and warn him about what's happening, Jack kicks them off of his property rather than heeding their words.

Later on, after an altercation with his wife in which he nearly bites her, he climbs to the window of an undressing woman and shows clear signs of his desire to break in and devour her. Sam and Dean, who have been following Jack, charge into the woman's apartment with blowtorches, prepared to rescue her, but find that Jack has regained control of himself and retreated. Jack returns to his house with the apparent intention of reconciling with his wife and working to resist his transformation, but finds his wife bound by the hunter Travis. Travis quickly incapacitates Jack and binds him to a column.

At first, Jack begs Travis to spare his wife, but after learning that Travis intends to burn both of them alive (owing to the fact that Jack's wife is pregnant, and her baby will inevitably carry on the Rugaru gene), his hunger and desire to protect his wife lead him to break free of his bonds. Unable to resist, he sinks his teeth into Travis's neck and swallows his first bite of human flesh, transforming him into a full-blown Rugaru.

Season Five
Chuck Shurley mentions in "Swan Song" in the afterword of his last Supernatural book's manuscript that Bobby will hunt a Rugaru a week after Sam jumped into Lucifer's Cage and stopped the Apocalypse.

Season Six
In "Caged Heat", Sam and Dean capture a Rugaru and deliver it to Crowley's demons for interrogation on Purgatory's location.

Season Eight
While in Purgatory, Benny and Dean captured and interrogated a Rugaru who knew where Castiel was. After much threatening, Dean managed to get him to spill the location; and afterwards, Dean stabbed him through the neck with Ruby's knife.

Appearances

 * Season 4
 * Metamorphosis
 * Season 5
 * Swan Song (Mentioned Only)
 * Season 6
 * Caged Heat (The monster Sam and Dean hand to Crowley's minions)
 * Season 8
 * What's Up, Tiger Mommy? (Flashback only)
 * Southern Comfort  (Mentioned only)

Lore
Rugarus in traditonal folklore are completly different from the ones featured on Supernatural. In traditional Cajun/ Louisiana and Canandian folklore, a Rugaru is a monster that prowls the swamps to feed on the blood of humans.

People become Rugarus by being bitten by another Rugaru or being cursed by a witch. Some lore says that people become a Rugaru if they break lent. Once transformed into a Rugaru, they are cursed to be a blood sucking monster for a hundred and one days and must feed on human blood (not flesh) daily. A Rugaru's hunger for human blood is said to be insatiable and he possesses superhuman strength and speed.

Some lore claims that a Rugarous can be cured of their condition if someone drows its blood on the end of the hundred and one days. After that, they can't speak about it to anyone until the hundred and one days are over. If so, the victim will return as a Rugaru along with the person that cured them. Rugarous in traditional lore are said to fear frogs, are repelled by the sign of a Hexagon and salt, which will burn its skin if it comes into phyical contact with it. Just like in Supernatural, Rugarus can only be killed by fire or by decapitation.

Trivia

 * Rugarus, along with Shapeshifters, are one of the few monsters shown so far that reproduces almost solely by sexual contact with a human. The offspring that results is presumed to always be a dormant Rugaru.