Rugaru

Rugaru
Powers and Abilities	Superhuman strength, speed, and aggression
Vulnerabilities	Fire
Appearance	Human-like with black eyes (when feeding)
Episode(s)	4.04 Metamorphosis 5.22 Swan Song (mentioned) 6.10 Caged Heat

4.04 Metamorphosis

Travis asks for help from Sam and Dean. He once killed a rugaru, but unbeknownst to him, it had fathered a child that was adopted out after his death. Travis explains that the rugaru "gene" runs in families. Outwardly the rugaru can appear human for years, never knowing its true nature, but eventually it becomes consumed with a terrible hunger. During this time, it feeds on any meat it can get its hands on, until it finally gives in to the craving for human flesh. The rugaru will also demonstrate superhuman strength, and its bones will move under its skin. One bite of human flesh is all that's necessary for the rugaru to transform outwardly into a monster, at which point it can never appear or be human again. The only way to kill it is by setting it on fire, otherwise it will continue killing people to sate its hunger.

The hunter Travis argues that the rugaru only operates on base instinct and cannot be reasoned with. In the final stage of his transformation, Jack Montgomery is still able to communicate and demonstrate horror, anger, love and remorse. However it can't resist its hunger and kills and eats Travis. Sam finally burns it to death. However Jack's wife Michelle has escaped, bearing his child.

5.22 Swan Song

Chuck notes that soon Bobby will be hunting a rugaru alone.

6.10 Caged Heat

Sam and Dean hand a Rugaru to two demons working for Crowley in 6.10 Caged Heat.

In Lore

The rougarou, also spelled roux-ga-roux, rugaroo or rugaru, is a werewolf-like creature with lore from the French-speaking communities of southern Louisiana ("garou" means "a man who transforms into an animal"). It is disputed whether they are related to the monsters of Native American lore. More on the rougarou legends.