Mikaeus, the Unhallowed, Grim Poppet, and Krark-Clan Ironworks

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Grim Poppet on the battlefield
• Krark-Clan Ironworks on the battlefield

Steps

1. Activate Krark-Clan Ironworks by sacrificing Grim Poppet, adding
2. Grim Poppet dies, triggering its undying ability, returning it from your graveyard to the battlefield with two -1/-1 counters on it
3. Repeat

Results

• Infinite -1/-1 counters
• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers