Emmara, Soul of the Accord, Agatha's Soul Cauldron, and North Pole Patrol

Prerequisites

• Emmara, Soul of the Accord on the battlefield
• Agatha's Soul Cauldron on the battlefield
• North Pole Patrol in exile

Steps

1. Activate a creature using North Pole Patrol's ability by tapping it, untapping Emmara
2. Activate Emmara using North Pole Patrol's ability by tapping it
3. Emmara triggers, creating a 1/1 Soldier creature token
4. Resolve the Emmara ability from step 2, untapping another creature
5. Repeat

Results

• Infinite ETB
• Infinite creature tokens