Adaptive Operative

Mutate {3}{b/g}{b/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 under it.).
The first time this creature mutates each turn,
you may choose target creature card with
mutate from your graveyard with mana value
X-1 or less, where X is this creature's mana
value. Mutate it onto this creature without
paying its mutate cost.