Gigaros, Top Mosasaur

Emerge {5}{u}{u} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's converted mana cost)
Islandwalk, Trample, Ingest
{3}: Gigaros, Top Mosasaur gains Flying and -1/-1 until the end of turn.
If at any time you do not control an Island, you must sacrifice Gigaros, Top Mosasaur.