Legolas

Haste, archery (At any time a creature you don't
control is 1 damage away from being killed, you may
reveal the top card of your library. If it's converted
mana cost is greater than that creature's converted
mana cost, destroy that creature. Put the card revealed
this way on the bottom of your library. Use only once
per turn.)
{t}: Legolas can use archery twice this turn.