- "Your mother sucks cocks IN HELL!"
- —The Devil
The Devil (who might as well be just another demon) is an evil, satanic entity that the Nerd has encountered or referenced to in certain occasions. The Devil first appeared on the AVGN show in the Super Mario Bros. 3 and the Wizard episode, where it possessed the Nerd's SMB3 cartridge. Battle ensued and the Devil was finally defeated by the Nerd thanks to the help of Super Mecha Death Christ 2000 BC Version 4.0 Beta. The Devil reappeared in the Bugs Bunny's Crazy Castle episode, where he was in Hell, alongside the recently deceased Bugs Bunny/Woody Woodpecker and the Nerd. He also appeared on the Super Pitfall episode, where he was the demon fighting against an Angel for Pitfall Harry's soul whenever he died. During the Nerd vs. Critic battle, he possessed and fought alongside the Critic during the final moments of the brawl. However, both of them were defeated by the Nerd and Super Mecha Death Christ.
Finally, he also appears on the History of Super Mecha Death Christ, sometimes taking control of some of the Super Mecha Death Christ machines.