Donatello, the Brains, Mutagen Man, Living Ooze, and Scurry Oak

Prerequisites

• Donatello, the Brains on the battlefield
• Mutagen Man, Living Ooze on the battlefield
• Scurry Oak on the battlefield

Steps

1. Put a +1/+1 counter on Scurry Oak
2. Scurry Oak triggers, creating a creature token and a Mutagen token due to Donatello
3. Activate the Mutagen by paying due to Mutagen Man, tapping and sacrificing it, putting a +1/+1 counter on Scurry Oak
4. Repeat from step 2

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite creature tokens