Creature — Centaur Shaman 3/4, 1RG (3)
Rare
Whenever a player activates an ability that isn't a mana ability, Burning-Tree Shaman deals 1 damage to that player.
Gruul shamans are bent on punishing the civilized. Any act more complex than rubbing sticks together or eating with utensils is met with the stinging burn of their magic.
Illus. Dan Scott

2/1/2006: A mana ability is an ability that adds mana to your mana pool, not one that costs mana to activate.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern