The Ooze, Yahenni, Undying Partisan, March of the Machines, and Thunderous Velocipede

Prerequisites

• The Ooze on the battlefield
• Yahenni, Undying Partisan on the battlefield
• March of the Machines on the battlefield
• Thunderous Velocipede on the battlefield

Steps

1. Activate Yahenni by sacrificing a creature with a +1/+1 counter on it
2. When that creature dies, The Ooze triggers, creating a Mutagen artifact token for each +1/+1 counter on the sacrificed creature
3. These artifacts are also 0/0 creatures due to March of the Machines
4. Each Mutagen artifact creature token enters with at least one +1/+1 counter on it due to Thunderous Velocipede
5. Resolve the Yahenni ability, giving them indestructible until end of turn
6. Repeat from step 1

Results

• Infinite artifact ETB
• Infinite artifact LTB
• Infinite artifact sacrifice triggers
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers