Blackwater, Ruling the Sea

{t}{1}: Put a 0/1 fish token with islandwalk into
play.
X{u}, Sacrifice X fish token: Search your library
for a fish, squid, crab or eel creature with a
converted mana cost of less than 2X and put it
into play tapped.
"Respect the ocean. It is older than you, and by the
time you have killed yourself with your own pollution
it will still be there to remember the promise you once
held."—Blackwater,
Guardian of the Greater Deep