Ratadrabik of Urborg, Leyline of Singularity, and Crosis's Attendant

Prerequisites

• Ratadrabik of Urborg on the battlefield
• Leyline of Singularity on the battlefield
• Crosis's Attendant on the battlefield
• available

Steps

1. Activate Crosis's Attendant by paying and sacrificing it
2. When Crosis's Attendant dies, Ratadrabik triggers, creating a token copy of Crosis's Attendant that is a 2/2 legendary Zombie in addition to its other types
3. Repeat using the Crosis's Attendant token

Results

• Infinite ETB
• Infinite LTB
• Infinite black mana
• Infinite blue mana
• Infinite death triggers
• Infinite red mana
• Infinite sacrifice triggers