Briarwood Colossus

Briarwood Colossus enters the battlefield tapped and doesn't untap during your untap step.
{1}{g}{g}: Untap Briarwood Colossus, creatures your opponents control cannot attack this turn.
{1}{r}{r}, {t}: Briarwood Colossus deals 5 damage divided as you choose among one or two target creatures and/or players.