10 Red Dwarf Episodes You Absolutely Must See
9. Polymorph
Now it's time to jump ahead to the third episode of Series Three, Polymorph. This episode sees the introduction of an iconic part of the show's mythos that would go on to be a recurring presence - the titular polymorph.
A genetically engineered lifeform, the polymorph burrows its way through Red Dwarf's hull after escaping from its containment unit. Able to shapeshift and steal emotions from its victims, the polymorph sets about stalking the crew, taking on a variety of forms in order to trigger specific emotional responses: A giant monster in order to steal Lister's fear; a seductive woman to steal Cat's pride; Rimmer in order to steal Kryten's guilt; and then Rimmer's mother to steal Rimmer's anger.
The result of all of this is comedic brilliance, as the cast get the chance to play wildly different versions of their characters: A gung-ho Lister; a pacifist Rimmer; a hobo Cat and an uncaring Kryten. It's such a clever and creative idea and the cast pull it off perfectly. Of course, by episode's end all is made right, but several more polymorphs would be seen over the years, making them a fan-favourite part of the show.
Of course, the greatest moment of the episode - and one of the funniest moments of the whole show - comes when the polymorph takes the form of Lister's underpants. Long story short, it ends with Rimmer watching Kryten straddle Lister with his groin attachment, trying to remove said underpants. Yes, you read that correctly.