Rimmer Monster

The Rimmer Monster was a deformed, deranged amalgamation of Rimmer's bio-printed clones after he accidentally jammed it in the episode, Officer Rimmer.

It was portrayed by Rimmer's actor, Chris Barrie, and several body contortionists, who wore masks molded after Chris Barrie.

Background
The bio-printer was recovered from the SS Nautilus after Rimmer "saved" it and its bio-printed captain, Edwin Herring (in-reality he tried to destroy it to prevent its oncoming collision with an asteroid storm, which would've sent off a nuclear blast).

The bio-printer was capable of printing artificial copies of individuals, however to prevent Rimmer from creating his own crew to command after his wrongful promotion, Lister and Cat wiped every crewmember from its databanks. Rimmer decided to instead make several copies of himself using DNA of his he found.

Role in the episode
After founding his own officers' club for him and his clones, Rimmer set about creating modified versions of himself to be his bodyguards after Lister and Cat decide to enter against his wishes.

An impatient Rimmer repeatedly pressed the print button, causing the bio-printer to backup and accidentally morph several copies of Rimmer into one hulking gestalt. The malformed creature chased Rimmer and Kryten, absorbing Rimmer's clones into it.

After regrouping, and forcing Rimmer to resign back to Second Technician, the crew formed a plan to take the beats down. After the Rimmer Monster finished absorbing all the Rimmer clones, they intended to absorb the "final Rimmer" being the original Rimmer. With Rimmer acting as bait, the crew snuck behind it, allowing enough time for Rimmer to take cover, before blasting it with bazookoids.