Creature — Human Assassin 1/1, 1BB (3)
Rare
{T}: Destroy target tapped creature.
Trained in the arts of stealth, royal assassins choose their victims carefully, relying on timing and precision rather than brute force.
Illus. Mark Zug

10/4/2004: Can't target itself because you choose the target before you tap him. At that time he is not yet a legal target.
10/4/2004: If the creature is no longer tapped when the Assassin's ability resolves, then the ability is countered.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern