Goblin Coliseum
Land (Rare)

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

Tap: Add R to your mana pool. If you played a land this turn, Add U to your mana pool instead.

UR: Goblin Coliseum becomes a 2/1 red and blue Ape creature until end of turn. It's still a land.

Jason Chippy