Buta, Scavenger Supreme

{r}{g}, {t}, Sacrifice a creature: Put a +1/+1
counter on Buta, Scavenger Supreme. If that
creature had power 4 or greater, untap Buta,
Scavenger Supreme. If this is the second time
you have used this ability this turn, transform
Buta, Scavenger Supreme
At first he went through the typical prey. It wasn't
long before his hunger grew insatiable