Phyrexian Monstrosity

Mutate {3}{p/u}{p/r}{p/w} (If you cast this spell for its
mutate cost, put it over or under target non-
Human creature you own. They mutate into
the creature on top plus all abilities under it.)
Whenever this creature mutates, it deals 2
damage to any target and you gain 2 life.
Creatures in your hand and that you control
on the battlefield have Mutate with its cost being
equal to that cards converted mana cost.