Mikaeus, the Unhallowed, Ashnod's Altar, and Slumbering Walker

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Ashnod's Altar on the battlefield
• Slumbering Walker on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Slumbering Walker
2. When Slumbering Walker dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect
3. Repeat

Results

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