text: Tartakovsky's former classmates McCracken and Rudish helped him design "Changes". This pilot went through several changes for a second cut, as Tartakovsky felt utterly dissatisfied with the score, the sound effects and the entire second half, which he chose to redo entirely. It was only then that producer Fred Seibert felt convinced that the concept for Dexter's Lab could be successful. Soon afterward, Tartakovsky helped McCracken create his own short film for World Premiere Toons/What a Cartoon!, which would eventually become the basis for The Powerpuff Girls. After finishing McCracken's project, the group proceeded to a second short film for Dexter's Laboratory, titled "The Big Sister". At the time, Tartakovsky was still not anticipating a series greenlight for Dexter's Laboratory. He went on to reminisce that, in those days, he was simply having fun working on short films with his friends. Tartakovsky and McCracken, who had been roommates shortly after college, went on to become regular collaborators on each other's series. Animation historian David Perlmutter noted a symbiosis between the two men, which he felt led to stylistic similarities between Dexter's Laboratory and The Powerpuff Girls.
  In August 1995, Turner ordered six half-hours of Dexter's Laboratory, which included two cartoons of one spin-off segment titled Dial M for Monkey. In addition to Tartakovsky, McCracken, Renzetti, and Rudish, directors and writers on Dexter's Laboratory included Seth MacFarlane, Butch Hartman, John McIntyre, Robert Alvarez, and Chris Savino. McCracken served as an art director on the series. Perlmutter described McCracken's role on Dexter's Laboratory as that of Tartakovsky's "effective second-in-command".
  Conception
  Dexter's Laboratory originated with one of Genndy Tartakovsky's designs of a ballet dancer. While attending CalArts, Tartakovsky drew a tall, thin girl dancing and decided to pair her with a short and blocky opposite. These two characters would eventually develop into Dee Dee and Dexter respectively, although they went unnamed until Tartakovsky started expanding the concept for Cartoon Network. To further contrast the two characters, Tartakovsky determined that Dee Dee would be artistic, while Dexter would be focused on science. In an interview, Tartakovsky said, "Dee Dee came first. She was really the star of the show to me. She was so much fun. Later on, I started on Dexter and he took over."