Trample Whenever an artifact is put into a graveyard from the battlefield, Molder Beast gets +2/+0 until end of turn.
"A trail of scrap metal can lead it into an ambush. But take care not to overfeed it." —Adaran, Tangle hunter
Official Rulings for Molder Beast
1/1/2011 : If Molder Beast and an artifact creature are both involved in combat during the same combat damage step, and that artifact creature is destroyed due to lethal combat damage, Molder Beast's triggered ability will trigger -- but it will get the bonus too late to affect that combat.