From The TV IV

Suctters are the ship's service robots. Each scutter consists of a motorized base with single mechanical arm and a three-fingered hand. Surprisingly, these apparently primitive robots are avid fans of John Wayne films, and have been known to play cowboys and indians on occasion. According to Rimmer, they even have a better union than some low-ranking crewmembers.

Dave Lister has developed a rapport with the scutter's over the years, in particular the one he calls Bob.