Legion

Created by some of the most brilliant minds of their time, Legion is a gestalt entity, a being who is quite literally nothing without others to provide him with existence. He takes the characteristics of any he meets and amalgamates them to give himself a personality and presence. The drawback with this is of course that anyone he meets must remain there or he ceases to exist. Legion, having the shared experience and knowledge possessed by his creators, has a brilliant mind, and knows all about art, science, technology, music and culture, as well as combat, medicine, and a hundred other skills. His quarters are stocked with masterpieces of art, which he himself has created.

When Lister and the others are captured by the malfunctioning directional buoy that brings them to Legion's lair, they unwittingly provide a presence again for the entity, who provides Rimmer with a new, indestructible and tangible hardlight hologram form, and extracts Lister's appendix, which had been about to burst. He provides them all with quarters filled with all the things they enjoy, but they are still prisoners: having failed to get Legion to join them, the boys are told that they may not leave, for if they do Legion will cease to exist.

Kryten finally figurs out the nature of the entity, and concocts a plan to help them escape, also receiving from Legion a superlight stardrive, which unfortunately blasts its way out of Starbug and flies off!