Werewolves in Supernatural have shapeshifting abilities and transform into a wolf-like creature. They are only one of the types of werebeasts seen in Supernatural, and share a lot of similarities with skinwalkers. Two types of werewolves exist. Most werewolves undergo involuntary transformation while asleep during the week before the full moon, but pure-blood werewolves can control their transformations and are not bound by the cycles of the moon. Appear in "Heart" (S02, E17), "Bitten" (S08, E04), "Sharp Teeth" (S09, E12), "Bloodlines" (S09, E20), "Paper Moon" (S10, E04), "Red Meat" (S11, E17), "Celebrating The Life Of Asa Fox" (S11, E06), "Ladies Drink Free" (S12, E16), "Wayward Sisters" (S13, E10), "Breakdown" (S13, E11), and "Let the Good Times Roll" (S13, 23).
- Absurdly Sharp Claws: Long claws when they transform.
- Blue Blood: Werewolves up to four generations removed from the Alpha Werewolf can control their transformations. They are also able to survive on the hearts of animals instead of humans.
- Cute Monster Girl: While Supernatural tends to have a marked male predominance in the cast, and this may be even more prominent when it comes to the monsters the Winchesters fight, there is more than one memorable female werewolf character.
- Enemy Within: Most of the werewolves shown in Supernatural are horrified by what they become.
- Horror Hunger: Werewolves have a very strong compulsion to eat human hearts, which is even more difficult to resist once they taste a human heart.
- Hunting the Most Dangerous Game: While werewolves are often discussed on Supernatural, they are rarely seen until Season 8, which leads Dean to be excited about the possibility of hunting one in 2007. In "Heart" (S02, E17), Dean says they have not hunted a werewolf since they were kids. Sam wrote an essay for school in 1997 on hunting a werewolf with Dean and their father in "After School Special" (S04, E13). Dean claims that the bruises on his wrists were caused by a werewolf in "Bad Boys" (S09, E07) when questioned about them by the leader of the boys' home he stayed at in 1995.
- Involuntary Shapeshifter: Regular werewolves are at the mercy of the phases of the moon and cannot control their transformations.
- Kryptonite Factor: Silver, usually in the form of a Silver Bullet, piercing the heart kills a werewolf. The blood of humans who have been drugged with the corn syrup additive created by the Leviathans, "Vamptonite", will kill werewolves as well.
- Laser-Guided Amnesia: Most werewolves do not remember what they did while in wolf form when they transform back into a human. Pure-bloods may be able to recall what they do in wolf form, resulting in Amnesiac Dissonance.
- Lunacy: Most werewolves transform during the week leading up to the full moon, but this does not have to hold true for pure-blood werewolves or if Eve is altering monster behavior.
- The Mind Is a Plaything of the Body: Werewolves are ruled by primal urges once they transform, and no longer have human inhibitions or morality. This is less pronounced in the werewolves who can control their transformations.
- More Teeth than the Osmond Family: Sharp fangs when they transform.
- Mysterious Animal Senses: Enhanced smell and sight.
- Never Sleep Again: The werewolves who undergo involuntary transformation only do so when asleep.
- No Ontological Inertia: Subverted Trope. You cannot cure a person who has become a werewolf by killing the werewolf who infected the person. In fact, as "Ladies Drink Free" reveals, to create the only viable cure for lycanthropy, you have to take the blood of the infecting werewolf while they are still alive; if you take it after they die, the cure won't work.
- Our Souls Are Different: Like other monsters, their souls go to Purgatory after they die.
- Picky People Eater: Werewolves eat hearts. A mauled body missing a heart is typical of a werewolf attack.
- Prefers Raw Meat: They tend to be out-of-control human-eating monsters who particularly like to chow down on fresh hearts. "Sharp Teeth" introduces a family of Friendly Neighborhood Werewolves who Resist the Beast and sit down for polite dinners of raw meat — though they cook proper steaks for their human guests.
- Super Reflexes: Enhanced speed and agility.
- Tragic Monster: Werewolves are often portrayed in a more sympathetic manner then other monsters in Supernatural. They are typically transformed into werewolves against their wills and are horrified by the savagery of their wolf forms.
- "Uh-Oh" Eyes: In werewolf form, the eyes become a bright unnatural color with slitted Hellish Pupils like a cat.
- Viral Transformation: One becomes a werewolf by being bitten by a werewolf.
- Voluntary Shapeshifter: Pureblood werewolves, especially those who are born one.
- Was Once a Man: Zigzagged. Some, like Madison and Garth were once men, but unlike vampires, werewolves can actually reproduce on their own (as in become pregnant and have kids). They are the biological descendants of the Alpha Werewolf. Garth's wife, Bess, is one such example.
- Wolf Man: Unlike skinwalkers, werewolves maintain their human proportions and stand on two legs. They have wolf-like features including fangs and claws.
Madison (Emmanuelle Vaugier)
Appears in "Heart" (S02, E17)
Madison works at a law office and lives at 1144 Minna Street in San Francisco, California. She meets Sam and Dean when they investigate the death of her boss, and Sam becomes attracted to her. Sam and she end up having sex after they mistakenly believe she has been cured of being a werewolf because Dean killed Glen, her enamored neighbor who was also the werewolf who transformed her.
- Commonality Connection: Sam can understand being transformed into a monster which frightens you to the point where you no longer want to live. The fact that she works in a law office may have also interested Sam, who majored in pre-law at Stanford.
- Crazy Jealous Guy: Kurt Mueller is a controlling and violent ex-boyfriend of Madison who continued to stalk her after she broke up with him.
- Genius Book Club: Dean tells Madison she is clearly smart because her "house is full of great books".
- I Cannot Self-Terminate: She is unable to end her own life, but is afraid she will hurt someone else when she transforms. She asks Sam to kill her.
- Killed Off for Real: Sam has to Mercy Kill her, as she doesn't want to live the rest of her life as a werewolf.
- Misery Builds Character: She decides to leave an abusive relationship and take control of her life after she is the victim of a violent mugging, where she is bitten on the back of the neck.Madison: What? Doesn't everybody think that being a victim of random violence is the best thing that ever happened to them?
- Sexy Secretary: Works as a secretary for a lawyer, Nate Mulligan, who tends to hit on her when he drinks.
- Staking the Loved One: Sam shoots her after she asks him to end her life.
Kate (Brit Sheridan)
Appears in "Bitten" (S08, E04) and "Paper Moon" (S10, E04).
Kate is a college student who has ambitions of being an environmental lawyer. She starts dating Michael Wheeler, who is transformed into a werewolf by one of their teachers, Professor Ludensky, who is a pure-blood werewolf. Their roommate, Brian Wilcox, develops feelings for her and transforms her into a werewolf, but she vows to only eat animal hearts and not to hurt humans.
- Cock Fight: Brian and Michael both want her.
- Deadly Hug: Gives one to her sister when she realizes that she can't save Tasha from her corruption.
- One Steve Limit: The other Kate is a vampire who appeared in "Dead Man's Blood" (S01, E20).
- Super-Powered Evil Side: She tears Brian apart after he stabs Michael with a silver knife.
- Sympathy for the Devil: Sam and Dean decide not to hunt her, as she has not killed any humans, but they vow to take care of her if she starts eating human hearts.
- Two Guys and a Girl: She hangs out with Michael and Brian.
- Triang Relations: Romantic Type 4 with Brian at A, herself at B, and Michael at C.
- Unusual Euphemism: Kate accuses Michael of foaming the runway and then leaving.
- Voluntary Shapeshifting: Able to control her transformation as a pure-blood werewolf.
- Walking the Earth: Kate is seen hitchhiking and walking along train tracks with a backpack at the end of "Bitten" (S08, E04).
Tasha (Emily Tennant)
Appears in "Paper Moon" (S10, E04).
Kate's sister, who was in a car accident that would almost certainly have been fatal before Kate turned her.
- Above Good and Evil: Thinks like this now. She sees her pre-werewolf state as weak and pathetic.
- Deadly Hug: Receives one from Kate, her sister, when Kate realizes that she can't save Tasha from her corruption.
- Horror Hunger: She doesn't think so. Tasha embraced the killing of innocent people and the eating of their hearts, even after Kate desperately tried to get her to control herself.
- Killed Off for Real: By Kate.