Nautilus, Titan of the Depths

Eminence - Whenever a land enters the battlefield
under an opponent's control, they may pay one, otherwise Nautilus, Titan of the Depths gets a
+1/+1 counter. Counters remain on Nautilus as
it moves to any zone.
Trample, vigilance, menace
Krakens, Leviathans, Octopuses, Serpents, and
Sharks cost {x} less to cast, where X is the
number of islands you control.