Putrid Goblin, Cayth, Famed Mechanist, and Goblin Chirurgeon

Prerequisites

• Putrid Goblin on the battlefield
• Cayth, Famed Mechanist on the battlefield
• Goblin Chirurgeon on the battlefield

Steps

1. Activate Goblin Chirurgeon by sacrificing Putrid Goblin When Putrid Goblin dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
2. When Putrid Goblin enters, its fabricate ability triggers, putting a +1/+1 counter on it
3. Resolve the Goblin Chirurgeon ability
4. Repeat

Results

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