Rooters

Originally, Aggregor and Servantis worked in the Rooters part of the Plumbers, in which Sevantis helped Aggregor hone in on his Osmosian powers with more control akin to Kwarrel and Kevin, which would eventually lead to Aggregor building up an immunity to the "insanity" portion of his powers.
With this newfound immunity, Aggregor gave back to Servantis by acting as a catalyst to infuse him with Cerebrocrustacean DNA, as well as giving his lackeys the DNA of an Aerophibian and a Prypiatosian-B.
Fearing it would be shut down or seen as unethical, Servantis had Aggregor infuse Phil Billings with the DNA of a Terroranchula, only for the former to alter his memories so he wouldn't remember the event but have a subconscious urge to prevent their pet project from being discovered as a contingency plan.
Servantis located four young outcasts, siblings Helen and Pierce Wheels, Manny Armstrong, and Alan Albright, and Aggregor infused them with their respective alien species but had to alter their memories and get rid of them abruptly when Max discovered what was going on, causing him to shut down the Rooters. The abrupt end happened in the midst of infusing Alan with Pyronite DNA, causing him to be able to change between forms while the other three had permanent forms.
With the Rooters dispanded, Max kept tabs on the amalgam kids as well as a mutant named Cooper Daniels and eventually they became a team known as the Plumber's Helpers to focus on things that were a bit too small for the Protectors of Earth.
Aggregor, having forgotten about the Plumbers and been given a false past, set out on a mission to obtain Celestialsapien DNA, a plan put into his subconscious by Servantis in order to create the ultimate contingency plan against people like Ben, while Aggregor believes he is doing it for the sake of "fixing" the universe.
After learning of the defeat of Aggregor at the hands of Ultimate Kevin, Servantis and the Rooters broke into the Plumber base to find him, activating Phil's memories and Terroranchula form, which also lead to discovering the Amalgam kids, causing Servantis also reactivated their memories.
With the Amalgam Kids and Phil, the Rooters began tracking him down, with Cooper warning Gwen of it, sparking them to team up to keep the Rooters from getting to him.