Carc, Keeper of Lore

+1: Carc becomes a +X/+X creature with Defender until end of turn. X being Carc's loyalty.
0: Choose one creature, they are now a crab in addition to their other types.
-3: Search your library for a Crab card, you may play that card as if it had mutate, it's mutate cost being the same as its mana cost.