The Great Rumpus Cat is a featured character in Andrew Lloyd Webber's Cats. He appears only in "The Awefull Battle of the Pekes and the Pollicles," a short play put on by the Jellicles to entertain Old Deuteronomy.
The Japanese production uses the name "Rumpus Cat" for an ensemble cat.
The 2016 Broadway Revival has changed the context of The Awefull Battle of the Pekes and the Pollicles, rather than being perfomed to entertain Old Deuteronomy prior to the Jellicle Ball, the number is used as Gus's reminiscence in place of Growltiger's Last Stand. Gus performs a very different take on Rumpus Cat in a long, flowing cloak.
As the Rumpus Cat only appears in the context of Pekes and Pollicles, his only interactions are with Munkustrap, the narrator. He is very enthusiastic but somewhat a fool; he misses his cues, misunderstands commands, and only just avoids kicking Munkustrap. However, the Pekes and Pollicles are suitably intimidated by his presence.
The Awefull Battle of the Pekes and the Pollicles is a play put on by the Jellicle Cats to impress and entertain Old Deuteronomy. As the story is most likely fictional, that means the Great Rumpus Cat likely is too, just an urban legend. Rumpus Cat is played by one of the tall ensemble toms, depending on production, often Alonzo, Plato or George.
The Great Rumpus Cat is portrayed as a kind of superhero to the Jellicles; as such, his appearance is stylised, with a glowing red eye-mask as eyes, a thin tail and a sleek black coat. On his chest is a Superman-style "R" logo.
In the Original London Production in 1981, Alonzo didn't wear a separate costume for Rumpus, only the logo was detachable over a black costume. However as the show developed Alonzo soon established his own black and white costume, with the Rumpus Cat being a quick change suit pulled over the performer's regular costume.
An ensemble character named "Rumpus Cat" appears exclusively in the Japanese production. The production varies considerably from the normal replica productions, and rather than having Alonzo, the production has two tall male ensemble, Gilbert and Rumpus Cat. Rumpus' design has varied significantly over the years, however his most recent look is recognisably related to the black and white Alonzo. Gilbert's look is similarly related to the black and gold Alonzo design.