— Duane Dibbley ("Back to Reality")
Duane Dibbley or Dwayne Dibley is one of the alter-egos of Cat. Duane Dibbley was a geeky human instead of a self-obsessed Felis sapiens, without any of his cat instincts, intuition, vanity or dress-sense.
Duane is introduced in "Back to Reality", Series 5 Episode 6. The Red Dwarf crew came across a Despair Squid, a sea-creature that secretes a venom which brings on hallucinations that makes your worst nightmares come true, thus driving its victim to suicide, Cat's hallucination caused him to lose his cool and style, thus creating his alter-ego, Duane Dibbley. Described by Ace Rimmer as looking so geeky he couldn't even get into a Science-Fiction convention, Duane displays many geek stereotypes; such as having a thermos flask, toothbrush, triple thick condom and extra strength spot cream. He has a large overbite, a pudding basing haircut and dresses in unstylish clothing. Cat calls his version of himself the 'Duke of Dork' and also the 'Prince of Dorkness', and describes him as "a no-style gimbo with teeth the druids could use as a place of worship". With all his illusions of style and charisma ripped away by his transformation, Duane was prepared to commit suicide alongside the rest of the crew. Luckily, Holly woke the crew up by having Kryten release Lithium Carbonate into Starbug's cabin before they committed suicide.
In "Flashback", Cat has a flashback to the hallucination caused by the Squid's ink, believing that once again he is Duane Dibbley. In the hallucination, after Duane and his friends shot themselves with a single bullet, the bullet never escaped from Billy Doyle's skull, leaving Duane the only survivor. Duane was blamed for the murder of his three friends, and must now undergo medical tests for his sanity. Meanwhile, back on Red Dwarf, Holly informs the crew that Cat is hallucinating. Kryten prepares the Lithium Carbonate and sprays it on Cat, bringing him back to sanity. When Cat comes around, he finds that he has been threatening to slice his own throat with a herring.
Duane appears again in "Emohawk", when Cat's sense of cool is stolen by an Emohawk. Cat is horrified that he has once again become Duane.
In "Back in the Red, Part 2", Cat revives Duane once more, this time by donning false teeth and a mop head, in order to assist his crewmates' escape from Red Dwarf. On this occasion Lister, Kochanski, Kryten and even two skutters also disguise themselves as the Dibbleys. Later, Duane has a "dance-off" with Blue Midget, which he finally wins when he changes back to Cat. (Ultimately, however, it's revealed that this is all within a computer simulation.)
It is also possible that Duane Dibbley exists in another universe and it is unknown to his origin in the case it could be that Cat encountered him after the events of Series VIII of those other facts through the nine-year journey. Following the dimension theory outlined in "Back to Earth, Part Three", a version of him does exist in the universe created as a result of the crew's hallucination in "Back to Reality".
He makes a special appearance on the special edition of Can't Cook, Won't Cook, Can't Smeg, Won't Smeg, in honour of the tenth anniversary of Red Dwarf, which reveals that Dibbley is a culinary genius.