Mortuary, Narcomoeba, Undercity Informer, and Sifter of Skulls

Prerequisites

• Mortuary on the battlefield
• Narcomoeba on the battlefield
• Undercity Informer on the battlefield
• Sifter of Skulls on the battlefield
• available

Steps

1. Activate Undercity Informer by paying and sacrificing Narcomoeba
2. When Narcomoeba dies, Mortuary and Sifter of Skulls trigger
3. Resolve the Mortuary trigger, putting Narcomoeba on top of your library from your graveyard
4. Resolve the Sifter of Skulls trigger, creating a 1/1 Eldrazi Scion creature token
5. Resolve the Undercity Informer ability, causing you to put Narcomoeba into your graveyard from the top of your library
6. Narcomoeba triggers, returning itself to the battlefield from your graveyard
7. Activate the Eldrazi Scion by sacrificing it, adding
8. Repeat

Results

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