Momo the Devourer

{x}{g/u}{u/b}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes Monstrous.)
When Momo the Devourer becomes monstrous,
each player sacrifices creatures whose power is
less than the number of +1/+1 counters on
Momo the Devourer. If the number of creatures
sacrificed this way is greater than Momo the
Devourer's power, sacrifice it and draw two cards.