Mishra's War Machine

Artifact Creature - Juggernaut 5/5, 7 (7)
Banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)
At the beginning of your upkeep, unless you discard a card, tap Mishra's War Machine and it deals 3 damage to you.¹
Illus. Amy Weber

Gatherer Card Rulings [Nov 2009]

• 10/4/2004: You may choose to take damage or to discard. You can't avoid taking damage if you have no cards to discard.
• 10/1/2008: If a creature with banding attacks, it can team up with any number of other attacking creatures with banding (and up to one nonbanding creature) and attack as a unit called a "band." The band can be blocked by any creature that could block a single creature in the band. Blocking any creature in a band blocks the entire band. If a creature with banding is blocked, the attacking player chooses how the blockers' damage is assigned.
• 10/1/2008: A maximum of one nonbanding creature can join an attacking band no matter how many creatures with banding are in it.
• 10/1/2008: Creatures in the same band must all attack the same player or planeswalker.
• 10/1/2009: If a creature in combat has banding, it's controller assigns damage for creatures blocking or blocked by it. That player can ignore the damage assignment order when making this assignment.

Format Legality	Legal in Vintage, Legacy Banned in Extended, Standard
Printings (3/16)	Fourth Edition (Rare) Revised Edition (Rare) Antiquities (Rare)