Xavier Sal, Infested Captain + Animation Module + Thornbite Staff + Morselhoarder

Xavier Sal, Infested Captain

Animation Module

Thornbite Staff

Morselhoarder

How it works

1. Activate Xavier Sal's second ability by tapping it and sacrificing a creature.
2. When the creature dies, Xavier Sal triggers, untapping Xavier Sal.
3. Resolve the Xavier Sal ability from step 1, putting a +1/+1 counter on a creature you control and a -1/-1 counter on Morselhoarder
4. Animation Module triggers, holding priority, activate Morselhoarder by removing a -1/-1 counter from it, adding 1.
5. Resolve the Animation Module trigger, causing you to pay 1 to create a 1/1 Servo artifact creature token.
6. Repeat.
7. Once you have infinite +1/+1 counters among creatures you control, you may instead use Xavier Sal's first ability to get infinite copies of creature tokens you control.

This crafty loop turns Xavier Sal, Infested Captain—outfitted with Thornbite Staff to grant him an untap trigger whenever a creature dies—into an engine of endless growth. By sacrificing a creature to proliferate, you feed the Staff while placing a -1/-1 counter on Morselhoarder, whose own ability lets you clean away that counter for mana to fund the Animation Module. Every time counters spread, Animation Module creates a Servo token to keep the sacrifice fodder flowing, allowing you to eventually pivot Xavier Sal into populating your board with infinite creature tokens.