Ball Lightning (A25 121)

Creature — Elemental • Mana cost: {R}{R}{R} • Masters 25 • Rare

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

The most frightening storms are those not woven by nature's hand.

Illustrated by Trevor Claxton.