Voiced by Lex Lang
Locomon was seemingly the antagonist, bio-emerging and going on a rampage on the train tracks. Beelzemon tried to fight him on a new motorcycle but was easily brushed aside, destroying his motorcycle. Takato, Rika, and Renamon got on board Locomon, whose inside was like a regular train. Renamon tried to stop him by using Shellmon's Hydro Blaster on the engine, but the heat evaporated the water.
Meanwhile Yamaki had workers change the train's path to set Locomon to go back into the digital world, telling Takato to get off before this happened. Eventually a Parasimon possessed Rika, and his brother turned out to be possessing Locomon the whole time. Locomon later digivolved to GranLocomon. Guilmon destroyed the Parasimon possessing Rika, but the main Parasimon, by possessing Locomon and having him run on the tracks, opened a digital zone causing his gang of Parasimon to invade.
After Gallantmon destroyed Parasimon and the remainder of his gang, Locomon was released from his control. Saying his usual line "I wanna run! I wanna keep on running!" Locomon returned to the digital world.
- Locomon has a few similarities to the Forever Train from Star Fox, being controlled by a redneck and having its track changed to go into an area. Although while Locomon's track is set merely to send him back to the digital world, the Forever Train is set to crash into a fuel bunker and explode.
- His name is derived from the word "locomotive"