Yawgmoth, Thran Physician + Scurry Oak + Panicked Bystander // Cackling Culprit

Yawgmoth, Thran Physician

Scurry Oak

Panicked Bystander // Cackling Culprit

How it works

1. Cast Yawgmoth by paying 2.
2. When Yawgmoth enters the battlefield, Scurry Oak's evolve ability triggers.
3. Holding priority, activate Yawgmoth by paying 1 life and sacrificing a creature.
4. When the creature dies, Panicked Bystander triggers, causing you to gain 1 life.
5. Resolve the Yawgmoth ability, putting a -1/-1 counter on Scurry Oak and causing you to draw a card.
6. Resolve the Scurry Oak trigger, putting a +1/+1 counter on it, triggering Scurry Oak's second ability.
7. Holding priority, activate Yawgmoth by paying 1 life and sacrificing a creature.
8. When the creature dies, Panicked Bystander triggers, causing you to gain 1 life.
9. Resolve the Yawgmoth ability, putting a -1/-1 counter on Scurry Oak and causing you to draw a card.
10. Resolve the Scurry Oak trigger, creating a 1/1 Squirrel creature token.
11. When the Squirrel enters the battlefield, Scurry Oak's evolve ability triggers.
12. Repeat from step 6.

This elegant loop is fueled by Yawgmoth, Thran Physician, whose ability to sacrifice a creature and pay 1 life lets you draw a card while placing a -1/-1 counter on Scurry Oak. Because Scurry Oak continually alternates between receiving a -1/-1 counter and a +1/+1 counter (which immediately cancel each other out via state-based actions), its counter-based creation ability perpetually spawns fresh 1/1 Squirrel tokens to feed right back into Yawgmoth's sacrifice cost. Meanwhile, Panicked Bystander quietly sits on the board observing the carnage, its passive death trigger turning every sacrificed creature into a net-neutral life cushion that offsets the life you pay to Yawgmoth and keeps your engine running indefinitely.