It, Eater of Worlds

{3}, Sacrifice another creature: Exile target
creature from a graveyard. Put a number of +1/+1 counters on It, Eater of Worlds equal to the exiled creature's converted mana cost. Activate this
ability only as a sorcery and only once per turn.
At the beginning of your upkeep, you may have
It, Eater of Worlds become a copy of target
creature in a graveyard until end of turn except
it's a 3/3 and keeps its other abilities.