A werewolf is a human being who, upon the complete rising of the full moon, turns into a fearsome and deadly near-wolf. Werewolves can be easily distinguished from regular wolves by several small distinguishing characteristics, such as the pupils of the eyes, the snout shape, and the tufted tail. At all other times, they appear as normal humans, though will often seem to be ill as the full moon approaches. This condition is caused by infection with lycanthropy, usually occurring when a human is bitten by a transformed werewolf.