Arwen Undómiel, Elrond, Lord of Rivendell, Animation Module, and Crystalline Crawler

Prerequisites

• Arwen Undómiel on the battlefield
• Elrond, Lord of Rivendell on the battlefield
• Animation Module on the battlefield
• Crystalline Crawler on the battlefield

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 Crystalline Crawler
4. Animation Module triggers
5. Holding priority, activate Crystalline Crawler by removing a +1/+1 counter from it, adding
6. Resolve the Animation Module trigger, causing you to pay to create a 1/1 Servo artifact creature token
7. Repeat from step 2

Results

• Infinite ETB
• Infinite creature tokens
• Infinite scry 1