Rafi, Retro Racer is a rare Legendary Creature — Dinosaur Pilot card from Unknown Event (UNK), collector number RR04e.
When Rafi enters and at the beginning of the first upkeep in a game where it's your commander, there's mana burn and combat damage uses the stack for the rest of the game. (If you don't know what that means, ask somebody over 30.) {R}, Sacrifice Rafi: Each player adds {R}{R}{R}.