Nautilus, Titan of the Depths

Menace
As long as you are Deep, Krakens, Leviathans, Octopuses, Serpents, Sharks, and
Nautiluses cost {3} less to cast.
As long as you are Deep, Nautilus, Titan of
the Depths gains +8/+0. (you are Deep as long as your library has 15 or less cards in it)