Artifact Creature — Construct 4/4, 4 (4)
Rare
Trample
Volatile Rig attacks each turn if able.
Whenever Volatile Rig is dealt damage, flip a coin. If you lose the flip, sacrifice Volatile Rig.
When Volatile Rig dies, flip a coin. If you lose the flip, it deals 4 damage to each creature and each player.
Illus. Mathias Kollros

10/1/2012: If Volatile Rig is dealt damage by multiple sources at the same time (for example, multiple blocking creatures), its first triggered ability will trigger only once.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Standard (Type 2)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern