Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.) When Themberchaud enters the battlefield, he deals X damage to each other creature without flying (This creature can't be blocked except by creatures with flying or reach.) and each player, where X is the number of Mountains you control. You may exert (An exerted creatures won't untap during your next untap step.) Themberchaud as he attacks. When you do, he gains flying (This creature can't be blocked except by creatures with flying or reach.) until end of turn.