Mutation Vat

{2}, {t}: Sacrifice a creature you control, then
reveal cards from the top of your library until
you reveal a creature. Exile the revealed creature.
{5}, {t}: Return target creature from your
graveyard to the battlefield. It is a black zombie
in addition to its other colors and types. It's base
power and toughness are reduced to 2 and it
enters the battlefield with a number of +1/+1
counters on it equal to the power of the exiled
creature.