Numot, the Devastator
Legendary Creature — Dragon
Flying
Whenever Numot deals combat damage to a player, you may pay 
. If you do, destroy up to two target lands.
Dan Dos Santos
Planar Chaos (PLC)
• #160Rulings
You choose the targets when the ability is put on the stack, and you choose whether to pay when it resolves. You may choose zero targets. You can pay the mana even if you chose zero targets.
(wotc • 2007-02-01)
Rulings
You choose the targets when the ability is put on the stack, and you choose whether to pay when it resolves. You may choose zero targets. You can pay the mana even if you chose zero targets.
(wotc • 2007-02-01)