Atom Smasher

Power Up (Whenever this creature deals combat
damage to a player, if it does not have a +1/+1
counter on it, put a +1/+1 counter on it.)
Remove a +1/+1 counter from Atom Smasher:
Destroy target noncreature permanent.
Whenever your opponent casts a spell during
your turn, Atom Smasher gains +2/+2 and
trample until end of turn.