Voiced by Brianne Siddall
Calumon was originally the Light of Digivolution, until it was transformed into him by the DigiGnomes.
One day Calumon ran through a digital area between Earth and the digital world being chased by the evil Maildramon, until DarkTyrannomon came to his rescue, destroying Maildramon, but in the process sending Calumon flying to Earth. Calumon would often mistake things like cars and soccer balls for Digimon. The symbol on his forehead glowed every time a Digimon digivolved, and appears to be the one who makes this possible.
After drawing on the soccer pitch with chalk, Calumon was mistaken for aliens, ghosts, or even demons, and nearly ran into Jeri at one point. Eventually Takato and Henry met him for the first time, and while they tried to find a tamer for him, he and Guilmon drew a chalk drawing of the symbol on Calumon's forehead, inadvertently causing Vilemon to bio-emerge. After Vilemon's defeat, Calumon ran off, and Takato and Henry decided that he didn't need a tamer.
Calumon was present during many battles, but was eventually discovered by Makuramon to be the one Zhuqiaomon was looking for. Jeri wanted Calumon as his tamer, but when Kumbhiramon attacked, revealed to Jeri that he doesn't fight. Makuramon kidnapped Calumon and took him to the digital world. However, in a bizarre turn of events, Makuramon lost Calumon, who was rescued from his cage by DigiGnomes.
Calumon eventually found his way to the flag the tamers used to mark the spot where they arrived in the digital world, shortly after Rika, Renamon, Kazu, and Kenta, and later Takato, Guilmon, Henry, Terriermon, Jeri, and Leomon, were there, and wore it as a cape. He ran into Doggymon, who chased him around, and later Beelzemon, but then ran alongside the DigiGnomes and digivolved three Woodmon into Cherrymon. Makuramon and Majiramon noticed this, but by the time they arrived, Calumon fell into a crevice leading to the forest area.
It was here that Calumon saved Rika from the river, after which they and Renamon were sent back to the desert by another wave of water, but Renamon digivolved to Kyubimon, after which the three reunited with Takato and the others. This reunion was short-lived, as Caturamon captured Calumon and imprisoned him in a pit in the Land of the Sovereign. Zhuqiaomon wanted him to digivolve him past the Mega level.
As Calumon was climbing out, the blobs of chaos, part of the D-Reaper, appeared alongside him, destroying everything they touched. Eventually Calumon was rescued by Sakuyamon, Ryo, and Cyberdramon. As a battle between Digimon and the D-Reaper drew near, Azulongmon had Calumon unleash the light of digivolution, digivolving all wild Digimon in the digital world to Mega. Azulongmon said Calumon could remain a Digimon if he wanted to, which he did.
After return to Earth, Calumon and Beelzemon tried to rescue Jeri from inside the D-Reaper's brain, but Calumon became trapped inside the brain while Beelzemon was trapped by its tentacles. Calumon remained imprisoned with Jeri for the remainder of the battle, until Leomon's ghost blasted a hole in the D-Reaper's head and Calumon projected a shield around himself and Jeri, and they and the others were taken out of the chaos by MarineAngemon shortly before the D-Reaper's demise. Due to the effects of Juggernaut Calumon was temporarily forced to return to the digital world.
Calumon was often seen with Jeri during the battle with the Parasimon.
Calumon doesn't fight, but he possesses the Light of Digivolution, enabling Digimon to digivolve.