Kryten 2X4B-523P most commonly referred to as Kryten is the teteragonist of Red Dwarf. He was originally the service mechanoid on board a ship known as the Nova 5 but after accidentally killing the crew was taken in by the boys of the dwarf for a new life.
He was portrayed by David Ross in his first appearance and by Robert Llywellyn in all later appearances.
After being taken on board Red Dwarf Arnold Rimmer immediately took advantage of his desire to serve people and gave Kryten several tasks, upon discovering this Dave Lister attempted to make Kryten break his programming and start living free by showing him various Marlon Brando movies. At first his attempts seem to be useless but then Kryten rebels against Rimmer and trashes the room much to Lister's approval. He then asks to borrow Lister's bike and leaves the ship on it. He eventually crashes on a moon planet and is rescued by the crew however his original personality and appearance were damaged, during repairs he assists Dave Lister during his pregnancy (after being impregnated in an alternate universe) and then goes on many misadventures with the crew. He gets along well with all of the crew and would do anything for any of them, despite still finding some of Rimmer's antics ridiculous. He also appears to be the only one to put up with Cat's selfishness and narcissism. After Kristine Kochanski boards the ship Kryten becomes very insecure and emotional and begins to think that he will get kicked off the ship, he eventually warms up to her however. After Kristine left upon getting depressed over Lister's worsening condition Kryten lied to protect his friend's feelings and told him she was sucked out of an airlock, he eventually did tell the truth however. Currently Kryten still goes on his various journeys with his friends and has broken most of his programming.
- David Ross was replaced in the role by Robert Llywellyn due to David being unavailable for filming.
- In series 7 he takes the role of triagonist since Rimmer exited the show becoming the new Ace Rimmer leaving the Cat to become the deuteragonist and Kryten's role of teteragonist was taken by Kochanski.