The Zassacre Zirl (Unknown Event #RB06)

The Zassacre Zirl {5}{B}{B}

Legendary Creature — Human Assassin

When The Zassacre Zirl enters the battlefield, if you cast them, destroy target commander an opponent controls. If its owner has two or more commanders, that card stops being a commander.

Whenever another Commander dies, draw a card.

4/4
Standard
Alchemy
Pioneer
Historic
Modern
Brawl
Legacy
Timeless
Vintage
Pauper
Commander
Penny
Oathbreaker