Burgeoning Ambusher

Cowardly (Whenever an opponent casts a spell, tap Burgeoning Ambusher. If one or more spells were cast last turn, Burgeoning Ambusher doesn't untap during your untap step.)
Heroic - Whenever you cast a spell that targets Burgeoning Ambusher, it gets +2/+2 until end of turn. Untap it.