lycanthropy
wolf-man delusion
Today this word meansThe condition of believing oneself a wolf. In pop culture, werewolf transformation itself.
Lykos (wolf) + anthropos (human).
Lycaon, the Arcadian king turned into a wolf for testing a god, is counted as the archetype of the transformation tale.
Plato and Pausanias both recorded that Arcadia really did pass down a story that whoever ate human flesh at the altar of Zeus became a wolf.
Worth noting
The word is assembled from the common noun lykos, not from the king's name. The name Lycaon comes from the same word.