Putrid Goblin, First Day of Class, and Altar of Dementia

Prerequisites

• Putrid Goblin on the battlefield
• First Day of Class in hand
• Altar of Dementia on the battlefield
• 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 Altar of Dementia 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 Altar of Dementia ability from step 2, causing target player to mill cards equal to Putrid Goblin's power
6. Repeat from step 2

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill