Visible crew/equipment: When the Red Dwarf crew are talking about who Legion is (after Lister has poured his bucksfizz), Kryten then says, "Could our very presence here have inadvertently awoken him?" As he says this, at the left side of the screen The End of a camera lens pulls away. (00:20:30)
Revealing mistake: When Legion gets hit, you can see his real face for a second when he adjusts his mask. (00:21:30)
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 ★