Oko, Rebel Shapestealer

+2: Reveal the top card of your library. If it is a creature card, you may have Oko becomes a copy of it until end of turn. Otherwise, draw a card.
-2: Target creature or artifact loses all abilities and types and becomes a Food Artifact. It gains {2},{t}:Sacrifice this artifact: You gain 3 life.
-7: All permanents in play lose all abilities and become 3/3 Elk creatures until end of turn. Prevent all damage done to creatures you control.