Boris, along with all other Earth robots of his generation, owed his advancement to Alistair Gryffen. Before his thought matrix, which allowed a robot to think for itself came along, robots were nothing more than windup toys. Boris was distingushed from his partner Chuckles by his red ascot and a black dot with a B on his forehead. He communicated with Chuckles with a claxon. Boris and Chuckles were clowns at the circus. Balloons were his act and kids loved it.
Boris and Chuckles were taken by Freddie Maxwell to fight in Crashclub, Freddie thought Boris was one of his best, a real contender. When K9 Mark 2 went undercover to take Freddie down, his crate was taken to the gladiator pens. Chuckles introduced himself and Boris. They met the champion, Pain-Maker, whom the clowns feared. They were excited K9 was their new roommate and showed him around, even though the walls were the only interesting feature. K9 saw Boris blow up a balloon, let the air out over and over again. Chuckles explained that balloons were Boris' act in the circus.
Freddie called Boris into the ring to face the Pain-Maker. The Pain-Maker tried to strike but he evaded the attacks acrobatically. However, Boris was soon destroyed. When Thorne was revealed to be behind the scheme and made K9 face the Pain-Maker, who flashed Boris' ascot to taunt K9 into destroying him so Thorne could take K9's regeneration unit.
K9 refused to fire. He escaped the Pain-Maker's self-destruction. Freddie was put out of business and Crashclub was closed down. Boris was rebuilt with a new pink ascot and horn. Chuckles and he called K9 to thank him for shutting down Crashclub and Chuckles cheerily told K9 they were going back to the Circus. (TV: Robot Gladiators)