[1] The role of Jellylorum was originated by Susan Jane Tanner in the West End in 1981, and by Bonnie Simmons on Broadway in 1982.

Jellylorum was originally the subject of a T. S. Eliot poem entitled "The Naming of Cats".

Jellylorum serves as a caretaker for the elderly Gus: The Theatre Cat,[6] and the two sing a duet in the second act of the musical.

On stage, Jellylorum is usually depicted as a predominantly yellow calico or tabby cat.

In Cats, Jellylorum has four main singing parts: The role of Jellylorum is principally a vocalist part and is played by a soprano who is able to hit high C.[4][5][7] The role of Jellylorum was originated by Susan Jane Tanner in the original West End production in 1981,[8] and by Bonnie Simmons in the original Broadway production in 1982.