Creature — Elemental 6/1, RRR (3)
Rare
Trample (If this creature would assign enough damage to its blockers to destroy them, you may have it assign the rest of its damage to defending player or planeswalker.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Ball Lightning.
Illus. Trevor Claxton

2/1/2007: The creature is sacrificed at the end of every turn in which it is on the battlefield. There is no choice about what turn to sacrifice it.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern