Nyik-Nyook

Espionage {g}{g} - (You may pay an additional {g}{g} as you cast this spell. If you do, it enters the battlefield under an opponent's control.)
If you own Nyik-Nyook, you may play an additional land on each of your turns.
Whenever you cast a spell, if you don't own Nyik-Nyook, tap all lands you control, then empty your mana pool.