Hanna-Barbera Cartoons was the original parent company for Cartoon Network Studios, the company that produced Dexter's Laboratory. Hanna-Barbera was founded in 1957 by former MGM animators William Hanna and Joseph Barbera (both of which created the famed cat-and-mouse duo Tom and Jerry at MGM in 1940), when MGM shut down their original animation unit. Hanna-Barbera helped develop the standard limited animation techniques that were to be utilized for television animation. H-B's first TV series was the Ruff and Reddy show that year, and had their first big success in 1958 with The Huckleberry Hound Show. Over the years, Hanna-Barbera continued making various animated TV shows and introduced many popular cartoon characters of the time including The Flintstones, Yogi Bear, The Jetsons, Magilla Gorilla, Wacky Races, Scooby-Doo, and many others.
In 1991, Turner Broadcasting bought the Hanna-Barbera library, and in 1994, with the growing popularity of Turner's then-new cable channel Cartoon Network, Hanna-Barbera founded a division named Cartoon Network Studios, which was designed to produce new animation exclusively for Cartoon Network under the H-B brand name or Cartoon Network's name. With the premiere of World Premiere Toons in 1995, young H-B animator Genndy Tartakovsky created a pilot for "Dexter's Laboratory" to air on the show (later aired as a regular episode in the main series, retitled "Changes"), and the following year, Dexter was green-lit to become Cartoon Network's first "Cartoon Cartoon" animated series.
Initially, the ending of the show for Season 1 contained a logo for Cartoon Network Studios with a byline reading "A Division of Hanna-Barbera Cartoons," but for Season 2, the show was released under Cartoon Network Studio's parent company's name Hanna-Barbera Cartoons (by this point, Turner had merged with Time Warner), initially with the above-pictured logo at the end, and on the Ego Trip TV movie with the classic 1980s H-B CGI "Swirling Star" closing logo (which was also used on The Powerpuff Girls at the time).
Meanwhile in the late-1990s, other Cartoon Cartoons which Hanna-Barbera produced such as Johnny Bravo, Cow and Chicken, I Am Weasel and The Powerpuff Girls (the former three debuted in 1997, the latter debuted in 1998) were released under Cartoon Network Studio's parent company's name Hanna-Barbera Cartoons with a similar above-pictured logo at the end, except for The Powerpuff Girls which instead used the 1980s H-B CGI "Swirling Star" closing logo.
In 2001, Hanna-Barbera became an in-name-only unit, now owned by Warner Bros. Animation, and Cartoon Network Studios became a separate facility, dropping the use of Hanna-Barbera's name in 2001 following the death of William Hanna (all subsequent Dexter's Laboratory, The Powerpuff Girls and Johnny Bravo episodes and new Cartoon Network original series since then carry a Cartoon Network Studios logo and copyright.)