Deepwater Domesticator

Submerge (You may have this creature enter the battlefield with a -1/-1 counter on it. It can't be blocked as long as it has a -1/-1 counter on it.)
Whenever Deepwater Domesticator deals combat damage to a player, return it to your hand.
When Deepwater Domesticator enters the battlefield, create a 1/1 blue Fish creature token.