Ayula, Queen Among Bears, Scurry Oak, and Rukarumel, Biologist

Prerequisites

• Ayula, Queen Among Bears on the battlefield
• Scurry Oak in hand
• Rukarumel, Biologist on the battlefield
• Rukarumel on the battlefield with "Bear" chosen
• available

Steps

1. Cast Scurry Oak by paying
2. When Scurry Oak enters the battlefield as a Bear due to Rukarumel, Ayula triggers, putting two +1/+1 counters on Scurry Oak
3. Scurry Oak triggers, creating a 1/1 Squirrel creature token
4. When the Squirrel enters the battlefield as a Bear due to Rukarumel, Ayula triggers, putting two +1/+1 counters on Scurry Oak
5. Repeat from step 3

Results

• Infinite ETB
• Infinite creature tokens
• Infinite +1/+1 counters on Scurry Oak