The Devil is a one-time villain but a popular recurring character in the Angry Video Game Nerd web series, nonetheless it's still a recurring antagonist in other works of the hosting site, Cinemassacre.
In spite of the Angry Video Game Nerd being its most popular appearance, it originated in Cinemassacre original movie, Wizard of Oz 3: Dorothy goes to hell. This version of the religious antagonistic character is similar to a human-faced goat.
Angry Video Game Nerd
Its most antagonistic role came when the Nerd found several instances that "proved" that the game cartridge of Super Mario Bros 3 may have been a work of the devil, near the end of the episode the game starts moving on its own and talking to him in a demon-like voice. It comes as the definite proof that the cartridge was possessed when the devil comes out of it.
The devil is the stage boss of the level Thy Fart's Consumed in the video game, Angry Video Game Nerd Adventures.