When the series was announced on February 19, 2007, Coop's little sister, Millie, originally had light blue glasses, a purple bow tie on her dark blue hair, and a brown skirt. Her final design was later changed to a blue skirt, red glasses, and a pink bow tie on her hair. Also, Coop's dad, Burt was originally created with gray glasses. Then, it were black.
Kid vs. Kat first aired on Cartoon Network on March 7, 2008 in US. The series aired in Canada on February 13, 2008 as a 11-minute sneak peek. It premiered a week later as a regular series. The series, in the US currently airs on Fridays at 9/8c. In the UK, the show airs on Cartoon Network since April 4, 2008.