Arwen Undómiel, Elrond, Lord of Rivendell, and Herd Baloth

Prerequisites

• Arwen Undómiel on the battlefield
• Elrond, Lord of Rivendell on the battlefield
• Herd Baloth on the battlefield
• You have a way to cause a creature to enter the battlefield under your control

Steps

1. Cause a creature to enter the battlefield under your control
2. Elrond triggers, causing you to scry 1
3. Arwen Undómiel triggers, putting a +1/+1 counter on Herd Baloth
4. Herd Baloth triggers, creating a 4/4 Beast creature token
5. Repeat from step 2

Results

• Infinite +1/+1 counters on Herd Baloth
• Infinite creature tokens
• Infinite ETB
• Infinite scry 1