Tatterkite, Dross Scorpion, Cauldron of Souls, and Krark-Clan Ironworks

Prerequisites

• Tatterkite on the battlefield
• Dross Scorpion on the battlefield
• Cauldron of Souls on the battlefield
• Krark-Clan Ironworks on the battlefield

Steps

1. Activate Cauldron of Souls by tapping it, giving Tatterkite persist until end of turn
2. Activate Krark-Clan Ironworks by sacrificing Tatterkite, adding
3. Tatterkite dies, triggering its persist ability and Dross Scorpion
4. Resolve the Tatterkite trigger, returning it from your graveyard to the battlefield with no -1/-1 counters on it
5. Resolve the Dross Scorpion trigger, untapping Cauldron of Souls
6. Repeat

Results

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