The Last Day - S3-E6
Revealing mistake: You can tell Robert Llewellyn is reading his lines when Kryten receives the computer chip. He is looking much lower than the chip in his hand and it was obviously quite a complicated piece of dialogue to remember. (00:12:35)
Answer: Presumably he does, but it's never been used in any material related to the show. He is the only Cat left (as shown in Series 1), so even if he had once had a name, nobody would know it.
Moose ★