Thicket Cairns
Land-Swamp Forest (Rare)

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

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

BG: Thicket Cairns becomes a 2/1 green and black Squirrel creature until end of turn. It's still a land.

James Grant West