Remains of Colossus

Remains of Colossus enters the battlefield tapped
and doesn't untap during your untap step.
{t}: Add {c}{c}.
{3}: Untap Remains of Colossus.
{8}: Remains of Colossus becomes an 8/8
colorless creature with haste until end of turn. Sacrifice it at the beginning of the next end step.
"Whatever it was, we ought to be glad it is gone. It
would wipe out cities within seconds if it were evil."