Season 4, Episode 4:
MetamorphosisWritten by Cathryn Humphris.Directed by Kim Manners.Air Date: October 9, 2008.Dean catches Sam in the act of using his powers, exorcising a demon with his mind. He's not overly thrilled about this, but before they can have a big fallout, Sam's phone rings. It's Travis, another hunter, who wants help tracking down a rugaru in Carthage, Missouri. Rugarus look like normal people until they get really hungry and eventually turn to cannibalism. It's genetic. Travis killed this rugaru's dad, but lost the kid, Jack Montgomery.The Winchesters have different ideas on how to deal with it. Sam reckons they can't kill him until he gives them reason to— innocent until proven guilty and all that. Dean reckons they should deal with the problem before the body count piles up. Meanwhile, Travis discovers that Jack's wife is pregnant, which means the cycle is gonna start all over again. He attempts to burn them both and get it over with. Doesn't work out too well for him. Jack eats him and goes full-on monster mode.Sam and Dean arrive, and he manages to lock Sam in a closet and stares at unconscious Dean, trying not to eat him. Just as he is giving in, Sam bursts out and burns him alive. Kill It with Fire indeed. Dean is duly grateful, and later manages to say that though he doesn't have demon blood, he'll be there for Sam.
Body countFor this episode = 1 human and 1 rugaru.For the series so far = At least 267 humans (of which 3 were witches), 14 demons, 24 ghosts, 10 vampires, 6 changelings, 3 gods, 2 shapeshifters, 2 werewolves, 1 crocotta, 1 djinn, 1 rakshasa, 1 rawhead, 1 shtriga, 1 wendigo, 1 zombie, 1 rugaru, and 1 dog.
- Body Horror: One of the signs of Jack turning is his bones painfully shifting and moving of their own accord under his skin.
- Big Eater: Jack, the rugaru.
- Heroic Willpower: Jack tries hard to resist the urge to kill and eat Dean. His hunger eventually begins to overcome his control, but it lasts long enough for Sam to break out of the closet and kill him just before he succumbs to the hunger.
- Horror Hunger: Jack tries very, very hard not to eat humans. He actually does a remarkable job of it, until Travis threatens to burn his pregnant wife. Alive.
- I Can Explain: Sam says this when Dean finds out Sam's using his psychic powers.
- I'm a Humanitarian
- I Never Said It Was PoisonSam: It's just, our parents. And now we find out our grandparents too? Our whole family murdered, and for what? So Yellow Eyes could get in my nursery and bleed in my mouth?Dean: Sam, I never said anything about demon blood.
- Kill It with Fire: The only way to stop a rugaru.
- Nice Job Breaking It, Hero!: Jack's doing well at not eating human flesh until Travis chains Jack up with his wife and threatens to burn them both alive. Even then he barely manages to keep it together... then Travis informs Jack that his wife is pregnant.
- Papa Wolf: The event that leads Jack to fully turn is when Travis ties them up with plans on killing both of them. He begs him to kill him but let his wife go, but after Travis reveals that she is pregnant possibly with another potential Rugaru, he goes berserk, breaks free and takes a chunk out of his throat.
- The Power of Love
- The Secret of Long Pork Pies: Referenced in the episode when Travis explains what Rugarus eat and why they need to be killed.
- Then Let Me Be Evil: Jack tries very hard to suppress the proclivities of his monstrous side and to live as a normal human. However, Travis refuses to believe this can be done and continually goads Jack. When Travis kidnaps and threatens Jack's wife and unborn child, Jack decides to show Travis how truly monstrous he can be.
- Tragic Monster: Jack. Even though he's a monster, it's hard NOT to feel sorry for the guy.
- What Happened to the Mouse?: The fate of the pregnant widow is left unknown.