Sea Dweller Womp

Sea Dweller Womp enters the battlefield with a womp counter on it.
As long as Sea Dweller Womp has a womp counter on it, it has -2/+2 and can't attack.
Remove a womp counter from Sea Dweller Womp, Sea Dweller Womp gets +2/+0 until end of turn and is unblockable this turn. If you attack with Sea Dweller Womp that turn, it doesn't untap during your next untap step.