“Zed” is the name assumed by a robot created by Dr. Lieter Greenbox. Zed began life as Greenbox’s micro-brain repair unit. The Metallikats, badly damaged from a conflict with the SWAT Kats entered Greenbox’s lab and used the device to repair themselves. Somehow the machine became sentient and taking the name “Zed” it followed the Metallikats around. In the process, it built up an incredible array of armor around itself, due to the fact it had learned to dismantle machines and assimilate them around itself, increasing its size and strength.
Zed grew tired of the Metallikats’ lowly ambitions, and sought to find its purpose in the grand scheme of things, by any means necessary. When Mac Mange tried to control Zed, this angered the robot, who tore apart the gangster and assimilated him, to the horror of Molly Mange. The Enforcers tried to intervene, but their tanks and weapons were also absorbed by Zed. The SWAT Kats, too, fled following a brief and unsuccessful first run at the gigantic machine, which they referred to as “giant monster of the week.”
Shortly afterwards, Zed headed by Puma-Dyne. The SWAT Kats, with Dr. Greenbox, and Molly co-operating, since its target was the Mega Beam, but had a hard time getting past Zed’s “antibodies,” small, drone-like robots that sniffed out and destroyed anything non-metallic entering Zed’s body. Zed ended up assimilating Molly, too, and then fused with its by-then insane inventor, deluded into thinking that its purpose was to help Greenbox conquer the city. The SWAT Kats destroyed the micro-brain, the connection between the inventor and his creation, and Zed crumbled, a fraction of a second before he would have nuked the city.