Deeproot Pilgrimage + Kiora's Follower + North Pole Patrol

Deeproot Pilgrimage

Kiora's Follower

North Pole Patrol

How it works

1. Activate either of the creatures by tapping it, targeting the other creature.
2. If the tapped creature was a Merfolk, Deeproot Pilgrimage triggers, creating a 1/1 Merfolk creature token.
3. Resolve the ability from step 1, untapping the targeted creature.
4. Repeat.

This loop sets up an endless cycle of mutual activation between Kiora's Follower and North Pole Patrol, where each creature untaps the other to generate an infinite sequence of taps and untaps. While North Pole Patrol and Kiora's Follower do the heavy lifting of untapping each other ad infinitum, Deeproot Pilgrimage watches closely and capitalizes on the action, generating an endless army of 1/1 hexproof Merfolk tokens whenever the nontoken Merfolk tap.