A group of escaped convicts who sought to evade the Enforcers by hiding out in Megakat Swamp, where they unwittingly stumbled across Dr. Viper’s lair. The group of five were captured by Dr. Viper and a recently-revived Dr. Harley Street, who’d been recuperating in Viper’s lair. Street bit and converted all five prisoners, turning them into kat-Ci-Kat-A hybrids like himself, using them as his underlings to go and steal Super-Katalyst 566 from Megakat Biochemical Labs as part of (he thought) his and Viper’s plan to take over the city.

Instead, Street and all five converted prisoners, as well as the converted Enforcer rookie Gray Taylor, were betrayed and mutated even further than they already were by Viper using the very katalyst they’d stolen. While Street became an enormous black armored scarab, the convicts and Taylor were turned into hideous white grub worms. In this form, they burrowed to the Megakat Thermonuclear Plant, as part of Viper’s true plan; to cause the power plant reactor to go critical and melt down, irradiating Megakat City. Because of the plant’s proximity to Megakat Bay, the SWAT Kats were able to flood the building to cool the breached reactor, preventing it from going critical, drowning all of the mutated Ci-Kat-A beetle/grub worms in the process.