berserk: A Viking warrior who attacked with a crazed fury.

incubus: An evil spirit that lies atop persons in their sleep, especially a spirit that is believed to have sexual intercourse with women while they are sleeping.

loup—garou: A French term meaning "werewolf."

lycanthropist: One who suffers from the disease of lycanthropy.

lycanthropy: A delusion that one has become a wolf; taking on the form and characteristics of a wolf by witchcraft or magic.

porphyria: A metabolic blood disorder, usually hereditary, that may cause sensitivity to light, abdominal cramping, and the appearance of particular chemicals, called porphyrins, in the blood and urine, which cause the urine to turn purple.

transmogrify: To change or alter greatly and often with grotesque or humorous effect.

warlock: A man who practices the black arts of magic; a male witch.

werewolf disease: Refers to the mental condition of lycanthropy, in which...