Inky Depths

At the beginning of your upkeep put a Depth
counter on Inky Depths, then look at the top X
cards of your library where X
is the number of Depth counters on Inky Depths Submerge all Horror, Krakens, Whales, Serpents
and Octopuses from among them.
Their submerge cost is half their converted mana cost rounded up.