Nagai-Hebi, Lord of World-Sea

Nagai-Hebi isn't a creature unless you control at least seven Islands that are no other land types.
Lands are Islands in addition to their other types.
{u}: Tap or untap target nonland permanent.
{2}{u}: Target creature gains Islandwalk until the end of turn.
"The World-Sea hides the serpent's massive body well, making it a deadly commander of the waves."
-Totum's Guide to the Multiverse