Colfenor, the Last Yew, Gutter Grime, and Yahenni, Undying Partisan

Prerequisites

• Colfenor, the Last Yew on the battlefield
• Gutter Grime on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Cast the creature card in your hand by paying
2. Either that creature dies as a state-based action due to having zero toughness, or activate Yahenni by sacrificing that creature
3. Gutter Grime triggers, putting a slime counter on it and creating a X/X Ooze creature token
4. Activate Yahenni by sacrificing the Ooze
5. When the Ooze dies, Colfenor triggers, returning the creature card from your graveyard to your hand
6. Resolve the Yahenni abilities, giving Yahenni indestructible until end of turn
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite storm count
• Infinite creature tokens that are infinitely large