Dr. N. Zyme is a slightly absentminded biochemist who works at Megakat Biochemical Labs. He and his colleague Dr. Elrod Purvis co-developed Viper Mutagen 368, which the noble Zyme hoped would be used to end world hunger and deforestation. However the greedy Purvis wanted to sell Viper Mutagen 368, and tried to steal the formula when Zyme left for home.
Zyme returned for his reading glasses, catching Purvis in the act. His attempt to prevent his colleague from escaping resulted in Purvis spilling the mutagen onto himself, mutating him into Dr. Viper. Viper took Zyme hostage along with Mayor Manx and Deputy Mayor Briggs, planning to mutate them into half kat, half snake creatures like himself, but they were saved by the SWAT Kats.
Some time after this, Dr. Zyme came into conflict with his former colleague a second time when Viper sent several giant bacteria monsters to raid Megakat Biochemical. Zyme attempted to use the strongest antibiotics known to katkind against the monsters, but because Viper had made his bacteria immune, this failed. Zyme was then apparently killed when one of the monsters tried to eat him.
His death or survival is unclear at this time. Glenn Leopold described Zyme as “survivally challenged,” and Christian Tremblay said he “probably died.” However, he never actually dies onscreen: we see the bacteria monster’s hand come down over him and cut to a shot of the creature being distracted by Feral’s Enforcer chopper, suggesting Zyme could’ve escaped offscreen.