The Song of the Sea

Indestructible, islandwalk, ward - Sacrifice an Island

Each sea creature you control is all sea creature types
in addition to its other creature types. (Sea creatures
include Merfolk, Leviathan, Octopus, Serpent,
Kraken, Crab, Fish, Homarid, Jellyfish, Starfish,
Whale, Nautilus, Squid, Lobster, Oyster, Sponge,
Cephalid, Camarid, and Turtle)

Each land you control is an Island in addition to its
other land types.