Dio appeared in the Season Three episode, "Hooked on Monkey Fonics", where they were seen playing their most well known hit song, "Holy Diver", at South Park Elementary's Bay of Pigs Memorial Dance. The Fonics Monkey also joined them on drums.
Dio was a Heavy Metal/Hard Rock band led by Ronnie James Dio. They are described as a musical force of the '70s and '80s by Principal Victoria.
- Even though the band was still active at the time of this episode, the members likenesses do not match the band's line-up at the time.