Putrid Goblin, First Day of Class, and Sling-Gang Lieutenant

Prerequisites

• Putrid Goblin on the battlefield
• First Day of Class in hand
• Sling-Gang Lieutenant on the battlefield
• Putrid Goblin does not have a -1/-1 counter on it
• available

Steps

1. Cast First Day of Class by paying , causing all creatures that enter the battlefield under your control this turn to get an additional +1/+1 counter put on it
2. Activate Sling-Gang Lieutenant by sacrificing Putrid Goblin
3. Putrid Goblin's persist ability triggers, returning itself from your graveyard to the battlefield with a -1/-1 counter on it
4. Putrid Goblin enters the battlefield, triggering First Day of Class, putting a +1/+1 counter on Putrid Goblin
5. Resolve the Sling-Gang Lieutenant ability from step 2, causing an opponent to lose 1 life and you to gain 1 life
6. Repeat from step 2

Results

• Infinite death triggers
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers
• Infinite lifeloss
• Infinite LTB
• Infinite sacrifice triggers