Worldskin Chuuls

Whenever a land enters the battlefield under your control, you may have it become a Swamp. If you do, put a +1/+1 counter on Worldskin Chuuls.
Whenever a land enters the battlefield under an opponent's control, you may have it become a Swamp. If you do, put two -1/-1 counters on Worldskin Chuuls.