Werewolves or lycanthropes are mythical man-beast hybrid creatures that exist in the legends of many different cultures throughout the world. The transformation has been said to occur for many different reasons and in many different ways, but the most common form of the myth in horror stories today is the man who changes into a wolf or wolf-like beast on every full moon and who can turn others into werewolves by biting them.

A werewolf traditionally possesses supernatural strength and augmented senses as well as the natural hunting instincts and weapons of the wolf, like menacing jaws and claws. Therefore, they are formidable monsters and very hard to kill. One of the most ancient talismans against lycanthropy is the herb wolfsbane (said to have grown from the saliva of Cerberus, the three-headed dog guardian of the Greek underworld, when Hercules brought him up to the surface world). Other herbs that legends say are effective as werewolf repellents include rye, mistletoe, and mountain ash (rowan).

Werewolves are not affected by religious symbols like crucifixes and holy water (unlike their counterpart monsters, vampires), but in modern fiction, they are vulnerable to weapons containing silver, such as silver bullets or silver blades. The silver bullet is the most iconic anti-werewolf weapon, but in many stories, anything silver causes agonizing pain if it touches the beast. Therefore, to be most certain of killing the monster, a werewolf hunter should carry good quantities of wolfsbane, rye grains, mistletoe, and mountain ash leaves or wood, and be armed with a variety of well-made silver weapons.

Since it is likely that a werewolf will overpower a human in close combat, it is essential to have a gun or two custom-designed to shoot silver bullets at a long range; once disabled by the gun, the werewolf can be finished off if necessary using a sword or axe with a silver-plated blade.