In the show, Munkustrap functions as a narrator, singing several songs and introducing many of the other cats. He is also the protector and second in command of the cats, after patriarch Old Deuteronomy; and directs them in the "Awefull Battle of the Pekes and Pollicles". As the defender of the tribe, Munkustrap fights Macavity. He also seems to know Mr. Mistoffelees well, as he stops him from getting to Grizabella in the film and signals him to use his powers from time to time in the film. In the end he was the last one to touch and accept Grizabella back into the tribe.
He is usually depicted onstage as a tall, silver tabby cat. Although Munkustrap does perform a substantial amount of dancing in Cats, the role requires strong singing and acting as well. He is also to be thought of as Demeter's mate.