Melion is an anonymous Breton lai that tells the story of a knight who transforms into a werewolf for the love of his wife who betrays him.
One day while out hunting, Melion meets the daughter of the King of Ireland who tells him that she has never loved a man other than him.
Melion sees a beautiful stag, and his wife declares that she will die if she does not eat the flesh of this particular animal.
Still in the shape of a wolf, he stows away on a boat to Ireland, where he is persecuted by the sailors and the townspeople because of his lupine form.
After becoming a man again, Melion considers punishing his wife by transforming her into a wolf, but instead, he leaves her and returns to Britain with King Arthur.
The poem can be broken down into the following sections: This lai shares many plot features with Marie de France's Bisclavret and the anonymous Biclarel where the hero is also a werewolf.