Dr. Viper floods Megakat City with Katalyst X-63, an experimental formula that mutates any living thing it touches into grotesque, menacing versions of themselves.

The SWAT Kats race against time to stop an "undead" evil sorcerer named the Pastmaster, who intends to send Megakat City back into the Dark Ages. But first our heroes must battle their way back from the prehistoric past.

The SWAT Kats must battle the evil Dr. Viper's mutant blob.

Dark Kat invents a doomsday device creating the most desperate mission ever for the SWAT Kats. Will T-Bone and Razor defeat their arch-enemy or will Megakat City fade into darkness?

Hang on to your tails, Dr. Viper is here with a hideous army of plant monsters. Only T-Bone and Razor can stop him from turning Megakat City into a Mega-Swamp!

Two mobsters turned half-kat robot criminals, return from the grave to terrorize Megakat City. The SWAT Kats have their paws full with this dangerous duo.

While in the middle of a battle against sea monsters who are attacking KatCo oil tankers, the SWAT Kats become caught in of the Pastmaster's time portals, which appears out of nowhere and pulls them back into medieval times. There they find the evil wizard in the midst of laying siege to Megalith City, Megakat City's Dark Ages counterpart, with an army of mythological monsters (dragons, cyclopes, etc.) in an effort to force its ruler, Queen Callista, Callie Briggs' lookalike ancestor, to marry him. And that's not the only romantic complication! When Callista sees Razor pull a certain sword from a certain stone, she falls in love with him, causing T-Bone to become jealous.

Dark Kat and the fiendish techno-villain, Hard Drive, hold Megakat City in the palms of their paws when they lure the SWAT Kats into a trap.

An accident with an experimental diamond mining machine, the Gemkat 6000, somehow turns brutal convict Rex Shard, into a crystalline giant whose touch turns people and objects to crystal. And that's only the beginning of his new powers. Seeking revenge for his accident, Shard first sets his sights on getting Warden Cyrus Meece, whose greedy exploitation of his prisoners led to the ordeal in the first place, and the Gemkat 6000's inventor, Dr. Greenbox, all the while randomly ""crystallizing"" every location he comes across. Can the SWAT Kats find a way to reverse Shard's condition before it's too late?

While working on construction for the new marina, a crane pulls an old biplane from the bay.

It's an all out kat-fight to the finish when the Metallikats come storming back in the drivers' seats of two giant hi-tech turbo attack-robots.

An exploration probe returns from its mission in space and is taken to MASA where Dr. Harley Street discovers a yellow viscous substance oozing from inside the probe.

Lenny Ringtail, a crazy comedian, escapes his asylum and finds refuge in a magic shop.

Dr. Viper forms a fiendish alliance with Dark Kat and the Metallikats! The SWAT Kats scramble to expose this slithering, sinister plot. Can they save Megakat City?

The SWAT Kats are sent through a time portal.

An enormous spaceship arrives to steal the planet's water supply to sell to water-dependent aliens.

Razor quits the team, leaving T-Bone to fight alone.

Turmoil, a new female villain takes control of the skies.

Hard Drive deactivates the Turbokat's weapons.

The Pastmaster brings to life an army of mummy warriors.

The SWAT Kats go underground in order to rescue five miners who have disappeared.

The SWAT Kats must battle the awakened demon, Volcanus.

Dr. Elrod Purvis is mutated into the evil Dr. Viper.

The SWAT Kats enter an alternate universe where evil versions of themselves are wanted.

The SWAT Kats and Commander Feral fight to stop the Metallikats from robbing Megakat Dollar.