Acorn Catapult, Cacophodon, and Phyrexian Altar

Prerequisites

• Acorn Catapult on the battlefield
• Cacophodon on the battlefield
• Phyrexian Altar on the battlefield
• You have a way to give Cacophodon indestructible
• available

Steps

1. Give Cacophodon indestructible by any method
2. Activate Acorn Catapult by paying and tapping it, dealing 1 damage to Cacophodon and creating a 1/1 Squirrel token
3. Cacophodon triggers, untapping Acorn Catapult
4. Activate Phyrexian Altar by sacrificing the Squirrel token, adding
5. Repeat from step 2

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers