When Yawgmoth enters the battlefield, Scurry Oak's evolve ability triggers.
Holding priority, activate Yawgmoth by paying 1 life and sacrificing a creature.
When the creature dies, Moldervine Reclamation triggers, causing you to gain 1 life and draw a card.
Resolve the Yawgmoth ability, putting a -1/-1 counter on Scurry Oak and causing you to draw a card.
Resolve the Scurry Oak trigger, putting a +1/+1 counter on it, triggering Scurry Oak's second ability.
Holding priority, activate Yawgmoth by paying 1 life and sacrificing a creature.
When the creature dies, Moldervine Reclamation triggers, causing you to gain 1 life and draw a card.
Resolve the Yawgmoth ability, putting a -1/-1 counter on Scurry Oak and causing you to draw a card.
Resolve the Scurry Oak trigger, creating a 1/1 Squirrel creature token.
When the Squirrel enters the battlefield, Scurry Oak's evolve ability triggers.
Repeat from step 6.
This ingenious engine turns a ceaseless cycle of life, death, and adaptation into a virtually bottomless well of resources. Yawgmoth, Thran Physician acts as the master surgeon, converting a creature into a card by paying a single point of life while placing a -1/-1 counter on Scurry Oak. That -1/-1 counter is immediately neutralized by the +1/+1 counter from Scurry Oak's own triggered ability, which in turn spawns a fresh 1/1 green Squirrel creature token to restart the cycle. Meanwhile, Moldervine Reclamation quietly keeps your life total stable and your hand overflowing with every single creature sacrifice, letting you dig through your entire deck at will.