Gnar, The Missing Link

Haste
{x}{r}{g}Boomerang:Gnar throws his boomerang
to target creature dealing X damage
{4}{g}{r/g}Hop:Destroy target artifact, target
creature gains +1/+1 counter
{2}{g}Headpat: All creatures gain +1/+1 counter
Transform if player has dealt/taken 5 damage