Coral Leviathan

Whenever a land enters the battlefield under
your control, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
Whenever Coral Leviathan deals combat damage
to a player, you may search your library for a
land card, put it onto the battlefield, then shuffle
your library.
From the depths of the sea, it emerges, crushing all in
its path.