Monster of the Depths

Sacrifice five creatures: Monstrosity 5 (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)
As long as Monster of the Depths is monstrous it has reach, trample, forestwalk, and islandwalk.
{1}{g}{u}: Switch Monster of the Depths power and toughness until end of turn.