When Overgrown Marsh enters the battlefield, sacrifice it unless you pay 3 life.

: Add  to your mana pool. Activate this ability only if you control a Forest.

: Add  to your mana pool. Activate this ability only if you control an Island.

: Overgrown Marsh becomes a 2/2 green and blue Leech creature with trample until end of turn. It's still a land.