|First appearance:||Book One|
|Tamer:||Ai and Mako Terada|
|Armour level 1:||None|
|Armour level 2:||None|
|Armour level 3:||None|
|Ultimate level 1:||None|
|Ultimate level 2:||None|
|Mega level 1:||Beelzemon|
|Mega level 2:||Beelzemon Blast Mode|
|Mega level 3:||None|
Beelzemon is the Mega form of Impmon. The name is derived from the Hebrew word, Beelzebub, also meant as the Lord of Flies, a word also meaning devil. The red scarf tied around his arm is residual from his Rookie form, Impmon (In the Rookie form Impmon uses it on his neck).
Beelzemon appears when Impmon accepts Chatsuramon's offer. He could digivolve under one condition: he had to kill the Tamers and their Digimon. With this power, Impmon is able to warp digivolve into his Mega form. Calumon is the first Digimon he encounters, when briefly stopping on his motorcycle to see the fatigued Digimon. But Calumon failed to recognize the difference and asked for help, after instead being kicked out of the way and driven into the horizon. He later encounters the Tamers, Renamon being able to recognize him as Impmon.
However, the battle was interrupted by a fierce storm created by the reactivation of the Juggernaut program created by HYPNOS. He appears again at Digimon Sovereign Zhuqiaomon's Southern Gate to fulfill his task given to him by Chatsuramon. Being blinded with so much power he causes several injuries in the Tamer group and manages tokill Leomon leaving Jeri on a nervous breakdown. Takato angered at this sight consumed his hatred and made Guilmon digivolve into Megidramon, after Beelzemon killed Makuramon and defeated Megidramon and even load the Ultimate Data of Taomon and Rapidmon.
After Takato managed to see the mistake he had made he and Guilmon biomerged into Gallantmon. Nevertheless, he defeats him and manages to defeat the Deva Chatsuramon (originally to fight Lopmon for betrayal of the Sovereigns) and absorb its data, allowing him to regain the upper hand and defeat Gallantmon, but Guardromon distracts him with a Guardian Barrage and Gallantmon is able to defeat him. Luckily, his life was spared requested by Jeri, and ashamed at what he had done he dedigivolved and escaped, leaving him to the mercy of the Chrysalimon, who he once terrorized, leavinh gim badly bruised.
Double Impact: Rapidly fires powerful bullets from his two Berenjena shotguns.
Darkness Claw: Attacks enemies using his razor sharp claws.
Primal Orb: After copying Makuramon's data, Beelzemon is able to use his attack, which conceals his enemies in inescapable bubbles.