Agatha's Soul Cauldron, Deeproot Pilgrimage, and Kelpie Guide

Prerequisites

• Agatha's Soul Cauldron on the battlefield
• Deeproot Pilgrimage on the battlefield
• Kelpie Guide in exile
• undefined

Steps

1. Activate the nontoken Merfolk using Kelpie Guide's ability by tapping it
2. Deeproot Pilgrimage triggers, creating a 1/1 Merfolk creature token
3. Resolve the Merfolk's ability, untapping the other creature
4. Activate the other creature using Kelpie Guide's ability by tapping it, untapping the nontoken Merfolk
5. Repeat

Results

• Infinite ETB
• Infinite creature tokens