Temporcor

Flying, trample, last strike, shroud
Temporcor gets +1/+1 for each tapped land you
control.
Whenever Temporcor's power is 20 or more, it
becomes a land until end of turn with "{t}: Add
{c}{c}{g}{g}{u}{u}{r}{r}."
Appease {g}{u}{r}. (At the beginning of your upkeep,
sacrifice this permanent or pay {g}{u}{r})