Werewolves are a supernatural creature that appear similar to humans, except on the full moon, when they transform into violent wolves. White their appearance is similar to humans except when transformed, werewolves are also very hairy, and also often act more animalistic, or wolf-like. Humans can become werewolves if a werewolf scratches them, making this creature very similar to vampires. Werewolves and vampires are sworn natural enemies.
In the episode Blue Moon, Ethan Morgan and Benny Weir believe their classmate David Stachowski to be a werewolf due to his appearance and behavior. While Benny attempts to cast a spell to prove that David is a werewolf, he accidentally hits Ethan with the spell. Ethan then tries to touch David to get a vision from him, and is scratched by David. Although Ethan is transformed into a werewolf, it was caused by Benny's spell, as David was not a werewolf but a were-dog.