Rob Renzetti is well-known for his work on cartoons. While Oh Yeah! Cartoons! was around, Renzetti created several different animated shorts. Each nothing alike and hilarious. One of the cartoons was called My Neighbor was a Teenage Robot. Having a loyal fan base, the short later became its own cartoon, My Life as a Teenage Robot. For the short's new show, some changes were made for the best. For instance, Mrs. Wakeman was re-designed. Nowadays, she looks a lot older than she did in MNWATR. Also, Brad was given different hair, which was also an improvement, and Tuck was completely re-designed. He went from what Carlos Ramos calls "freaky-looking" to a much cuter design, which unexpectedly stole the hearts of tween girls ages 11-14. Jenny was also slightly re-designed, but only minor changes were made. Presumably to catch up with the appearance of new mellenium characters. Also, new characters were added, such as the love-struck geek Sheldon Lee, the devious, and very popular Krust cousins and the stuck-up Don Prima. My Life as a Teenage Robot, despite the seemingly endless delay in new episodes, has caught a loyal amount of fans like a certain yellow sponge catches jellyfish.
But, Rob Renzetti has done much more for the cartoon world than that. He was the director as well as supervising producer on Cartoon Network's Whatever Happened to Robot Jones?, which could've inspired some of the changes on MLAATR. Renzetti has directed many, many cartoons. He has had a big career, I can assure you.