After pizza is left in the middle of their room to lure them into the open, they initially fight one–by–one, disappearing once their health bars are depleted by half, and then reappearing together after each has had their initial 'turn'. They all wield melee weapons, have shell–like objects strapped to their backs, and are apparently acquainted with a woman named June.
The Splinter Group is secretly led by Flinter, who has to be lured out via a secret puzzle in the room accessed after killing the main group, and is significantly stronger than any of the main four individually are.
- Killing the Splinter Group in the order that they appear in completes the challenge Cut 'Em No Slack.
- Each of the four rats has an increased chance to drop a legendary Storm Front.
- It is possible to get multiple Storm Front's from the group, since their drops are independent of each other.
- The Splinter Group is a parody of the Teenage Mutant Ninja Turtles.