Xavier Sal, Infested Captain + Scurry Oak + Intruder Alarm

Xavier Sal, Infested Captain

Scurry Oak

Intruder Alarm

How it works

1. Activate Xavier Sal's second ability by tapping it and sacrificing any other creature you control, putting a +1/+1 counter on Scurry Oak.
2. Scurry Oak triggers, creating a 1/1 Squirrel creature token.
3. When the Squirrel enters the battlefield, Intruder Alarm triggers, untapping all creatures.
4. Repeat.
5. Once you have infinite +1/+1 counters on Scurry Oak, you may instead use Xavier Sal's first ability to get infinite copies of creature tokens you control.

This clever loop is centered around Scurry Oak, whose evolve and counter-trigger abilities turn any influx of +1/+1 counters into a fresh supply of Squirrel tokens. Every time a new Squirrel enters the battlefield, the passive global trigger from Intruder Alarm immediately untaps all creatures—including Xavier Sal, Infested Captain—allowing you to continually sacrifice your creatures to fuel Xavier's second ability for endless proliferations. By continuously cycling through this sacrifice-and-untap engine, you generate an unbounded number of death triggers, enter-the-battlefield events, and massive power for your board before finally pivoting Xavier Sal's first ability to populate your entire token army infinitely.