Wooded Coliseum
Land-Forest Island (Rare)

(Tap: Add G or U to your mana pool.)

At the beginning of your end step, if you didn't cast any spells this turn, Wooded Coliseum deals 1 damage to you.

1U: Wooded Coliseum becomes a 1/1 green and blue Treefolk Elf creature with flying until end of turn. It's still a land.

James Staples