The Gluttonous

Mutate {2}{g}(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 from under it.)
Devour 1(As this enter the battlefield, you may sacrifice any number of creatures. This creature enter
the battlefield with that many +1/+1 counters on it)
When this creature mutate you can sacrifice one Creature token, if you do, it gains +2/+2