This should have been a card in Dark Ascension. It literally turns someone into a werewolf! It's a tricky curse though, because whoever is a werewolf can't cast spells anymore, and ultimately becomes more fragile.
Here's a curse that's better in multiplayer. The guy that this is enchanting is probably going to be mad at you.
Here's a useful common curse that's almost discard. Nice in multiples!
Enjoy the curses this week!