Chroma, the Elemental

When Chroma, the Elemental enters the battlefield or attacks, choose one that hasn't been chosen this turn:
•Put a +1/+1 counter on target creature.
•Deal 3 damage to target creature or player
•Destroy target artifact or enchantment.
{bull}Put a stun counter on target creature
opponent controls.
{bull}Put a -1/-1 counter on target creature.