Phyrexian Breeding Pit

Phyrexian Breeding Pit enters the battlefield
tapped with two incubation counters on it.
During your untap step, if Phyrexian Breeding
Pit has an incubation counter on it, don't untap
it and remove an incubation counter from it.
{1}{p/b}, {t}, Sacrifice a creature: Search your
library for a creature with power equal to or
less than the sacrificed creature's power, put it
on the battlefield tapped under your control,
then shuffle. Activate only as sorcery.