Terrorform - S5-E3
Trivia: The Self-Loathing creature from "Terrorform" was based on an unused design from Doctor Who (1963).
Trivia: When Lister is trying to explain that he knows Rimmer, he mentions "Your middle name is Judas but you tell everybody it's Jonathan" This is a fun-fact because Chris Barrie's (who plays Rimmer) middle name is, in fact, Jonathan.
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 ★