He has also directed episodes of Drawn Together, Duckman, The Wild Thornberrys, Sit Down, Shut Up, and The Ren & Stimpy Show.

Avanzino had wanted to be a comic book artist after graduating from high school, but instead studied architecture; he started in the animation industry at Klasky Csupo to work for the second season of The Simpsons.

[1] After Klasky Csupo had their Simpsons contract terminated by Gracie Films in favor of Film Roman, Avanzino moved to Spümcø to work for The Ren & Stimpy Show; he was one of the few hires at the studio early on during production of the second season.

He served as a storyboard artist in episodes in the second season, storyboarding "Son of Stimpy"; after John Kricfalusi and Spümcø were fired for negligence, he transferred to Games Animation with his peers and directed "Stimpy's Fan Club", one of the series' most critically acclaimed episodes in place of Kricfalusi.

Aside from collaborations with 20th Television (Animation), he had also directed the first season of Clash-A-Rama!, which Rough Draft Studios produced on commission by Supercell based on their video game Clash of Clans.