Around that time, Rheingold got his first writing break - at MTV. Andy scripted a number of Beavis and Butt-head episodes, including the series finale. He followed that up by penning a Beavis and Butt-head book, Chicken Soup for The Butt, which was named "best parody book of the year" by Entertainment Weekly.
After the success of SpongeBob and Beavis, Rheingold was hired as a full-time staff writer for MTV Networks. For several years, he wrote for a handful of hit series including CatDog, All That, Kablam! Andy eventually moved up to Head Writer level, overseeing scripts on Undergrads for MTV, Codename: Kids Next Door for Cartoon Network, and Skunk Fu for the BBC and Cartoon Network.
Between his TV gigs, Rheingold writes feature films and he has sold scripts to Paramount Pictures, Disney, and Nickelodeon Movies. He has authored two original children's books—When Guinea Pigs Fly for Scholastic and Rupert and His 99 Sisters. Andy wrote The Little Spirit, an hour-long animated Christmas special for NBC starring Danny DeVito. The movie premiered during the 2008 holiday season.
- The Horn book guide to children's and young adult books. Horn Book, Inc. 2006. p. 63.