Eloise, Nephalia Sleuth + Cauldron Familiar + Peregrin Took + Umbral Collar Zealot

Eloise, Nephalia Sleuth

Cauldron Familiar

Peregrin Took

Umbral Collar Zealot

How it works

1. Activate Umbral Collar Zealot by sacrificing Cauldron Familiar.
2. When Cauldron Familiar dies, Eloise's first ability triggers, creating a Clue and Food token.
3. Resolve the Umbral Collar Zealot ability
4. Activate Cauldron Familiar by sacrificing a Food.
5. Eloise's second ability triggers, causing you to surveil 1.
6. Resolve the Cauldron Familiar ability, returning it from your graveyard to the battlefield.
7. When Cauldron Familiar enters the battlefield, it triggers, causing each opponent to lose 1 life and you to gain 1 life.
8. Repeat.

This loop turns a simple cat into an endless engine of life drain and deck manipulation by looping it through the graveyard and back. Umbral Collar Zealot provides the initial sacrifice outlet to feed Cauldron Familiar back to the graveyard, which triggers Eloise, Nephalia Sleuth to create a Clue token. Thanks to Peregrin Took's replacement effect, that token creation is upgraded to include an extra Food token, providing the exact sustenance needed to recur Cauldron Familiar and keep the cycle spinning infinitely.