Dinjalius, The Worldspire

Dinjalius, The Worldspire costs {1} less to cast
for each Aquatic creature you control. (Aquatic
creatures are Krakens, Serpents, Leviathans,
Octopuses, Merfolk, Squid, Fish, Whales, Sharks,
Sponges, Crabs, Homarids, and Starfish.)
When Dinjalius enters the battlefield, for each
other Aquatic creature you control, create a
token that's a copy of that creature.