Serpent of the Depths

Suspend 5 - {1}{u}{u} (Rather than cast this card
from your hand, pay {1}{u}{u} and exile it with six
time counters on it. At the beginning of your upkeep,
remove a time counter. When the last is removed, cast
it without paying its mana cost.)
When Serpent of the Depths comes into play
return all non-flying, non-Leviathan, and non-Islandwalk creatures to their owners' hands. All nonbasic lands in play are now basic Islands.