James "Jimmy" Horn was a male Human born in Florida, who served aboard Enterprise (NX-01) during its mission in the Delphic Expanse as ship's janitor. While serving aboard Enterprise, he was friends with an officer named Tom who was ship's barber until his death in the Expanse. After that, Jimmy took over that position which he was training for under Tom. While in Main Engineering, a spatial distortion risked a loss of containment in the warp core. Luckily, Jimmy quickly thought to plug a hole with his sweeper saving the ship, but his legs were severed in the process.