Putrid Goblin, First Day of Class, and Goblin Sledder

Prerequisites

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

Steps

1. Cast First Day of Class by paying Activate Goblin Sledder 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 Sledder ability
4. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinitely large creatures you control until end of turn