Putrid Goblin, First Day of Class, and Goblin Trashmaster

Prerequisites

• Putrid Goblin on the battlefield
• First Day of Class in hand
• Goblin Trashmaster on the battlefield
• available

Steps

1. Cast First Day of Class by paying Activate Goblin Trashmaster 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, First Day of Class triggers, putting a +1/+1 counter on Putrid Goblin
3. Resolve the Goblin Trashmaster ability
4. Repeat from step 2

Results

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