Gnawing Vermin + Phyrexian Altar + Underworld Breach + Yarok, the Desecrated

UBRG identity

Commander legal

The 4 combo pieces

What must be in place

You have at least three cards in your graveyard.

How to execute it

  1. Activate Phyrexian Altar by sacrificing Gnawing Vermin, adding {B}.
  2. Gnawing Vermin dies, triggering its second ability, causing target creature you don't control to get -1/-1 until end of turn.
  3. Cast Gnawing Vermin from your graveyard for its escape cost by paying {B} and exiling three other cards from your graveyard.
  4. Gnawing Vermin enters the battlefield, triggering its first ability twice, causing you to mill four cards.
  5. Repeat.

What the combo produces