Bomb

Flying
Bomb enters the battlefield with 4 explosion
counters on it. Whenever a player casts a spell,
remove an explosion counter from Bomb.
When the last explosion counter is removed,
sacrifice Bomb and it deals 2 damage to target
player and each creature that player controls.
"Hey, look behind you!" - Zidane
"I'll not fall for such an old trick!" - Steiner