The Right Arm of Pookie

Mutate {2}{w}{w}
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever this creature enters the battlefield or
mutates, put a stun counter on up to one target
creature, then tap up to X target creatures where
X is the number of times this creature has
mutated. (If a permanent with a stun counter would become untapped, remove one from it instead.)