The series follows the adventures of a cat and a dog who share a body, despite having opposite personalities. Cat is a strait-laced, intellectual cat whereas Dog is an impulsive, happy-go-lucky dog. The brothers share similarities with The Odd Couple, the Looney Tunes shorts and elements of Laurel and Hardy, Abbott and Costello, and fellow Nicktoon characters Ren and Stimpy. The series was produced by Nickelodeon Animation Studio and Peter Hannan Productions.
The series revolves around Cat and Dog, a golden-furred conjoined twin hybrid of a cat and a dog with two heads and shared body, with no tail or hind legs. Although they are best friends they have very different personalities, similar to "The Odd Couple" and the Looney Tunes shorts. The series takes place in Nearburg, a town dominated by anthropomorphic animals.