Ashnod's Altar, Caller of the Claw, and Nim Deathmantle

Prerequisites

• Ashnod's Altar on the battlefield
• Caller of the Claw on the battlefield
• Nim Deathmantle on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Caller of the Claw, adding
2. Caller of the Claw dies, triggering Nim Deathmantle, causing you to pay to return Caller of the Claw from your graveyard to the battlefield, and attach Nim Deathmantle to it
3. Caller of the Claw enters the battlefield, creating a 2/2 Bear creature token for each nontoken creature that died under your control this turn
4. Activate Ashnod's Altar by sacrificing a Bear, adding
5. Repeat

Results

• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers