Terio, Friend to Sharks

+2: You may put a +1/+1 counter on each shark you control. If you do, discard a card.
-1: All creatures you control are sharks in addition to their other types. Create a 2/2 blue shark creature token with defender.
-4: Gain control of a creature your opponent controls until Terio leaves the battlefield. It is a shark in addition to its other types.