Thomas Horner is a Jubilator driver and underground tunnel worker. He is responsible for tempting his co-workers into gambling on Jubilator Races, which he profits from. But is told off by his co-worker, Peter Thump, and denied a promotion by his supervisor Penelope Snug.
After going crazy from a bad batch of Joy, he attempts to kill Peter with the Jubliator, though Arthur defeats him. He dies by the gas inside of the jubilator filling up as he desperately attempts to open the glass on the vehicle.
- During his battle with Arthur he sings the Imperial German Empire National Anthem (1871-1918) in English, which shares the same melody as British Anthem "God Save The King". Peter first replies to Arthur "I knew he was patriotic, but not like that." this implies that he was an extreme nationalist.
- His name is a reference to character Thomas Horner from Shakespeare's Henry VI, Part II. In which he was an apprentice who betrayed his master Peter Thump by killing him.
- For some strange reason, he loses his hair, mustache and glasses as he dies in the Jubilator.