Kids' WB! was Warner Bros.' American children's programming division brand for The WB Television Network and later on The CW Television Network, originally broadcast from September 9, 1995, to May 17, 2008, after which The CW's Saturday morning programming slot was sold to 4Kids Entertainment to form The CW4Kids (which has since been renamed to Vortexx). Kids' WB! was re-launched as an online network on April 28, 2008, before the brand was finally retired for good in May 2015 (just a few months shy of the original block's 20th anniversary).
Animaniacs was the very first show to be broadcast as part of Kids' WB!, and as such, a lot of early hype for the programming block revolved around the fact that the show was moving there from Fox Kids. (Ironically, despite the show now airing on a network owned by the company that produced the show in the first place, the gag credits for subsequent episodes suggest that the writers had no love for the show's new home; examples being "Kids WB Is #1 - Ha! Ha! Just Kidding!" and "Be the First Kid on Your Block to Actually Watch The WB!") The WB aired a preview special titled Welcome Home, Animaniacs!, in which previews of each of the shows featured on the programming block were presented by the stars of the network's prime-time shows, alongside animation of Yakko, Wakko and Dot leaving the Fox network and driving to the WB studio. The show was aired on Kids' WB! on Saturday mornings and weekday afternoons from then until September 1999.
Alongside the third season of Animaniacs, the Pinky and the Brain spin-off series also debuted as part of Kids' WB!'s inaugural year, alongside fellow Warner Bros. cartoons The Sylvester & Tweety Mysteries and Freakazoid! and Universal Studios' Earthworm Jim. In its first season, Pinky and the Brain also aired as part of The WB's Sunday night line-up. By September of 1996, it was dropped from the Sunday night schedule, but remained on the Kids' WB!'s Saturday morning line-up through 1998 and on the weekday afternoon line-up until September of 1999.
In the fall of 1998, following the cancellation of Animaniacs, both shows were taken off of Kids' WB!'s Saturday morning line-up, but remained on weekday afternoons for the following year. It was in that season that Pinky, Elmyra and the Brain debuted on the Saturday morning block before being dropped from the schedule in January 1999. The final episodes of Animaniacs and Pinky and the Brain were aired together as The Animaniacs Super Special on November 14, 1998.
On January 16, 1999, Kids' WB! debuted The Cat & Birdy Warneroonie Pinky Brainy Big Cartoonie Show, a 90-minute show which combined segments from Animaniacs, Pinky and the Brain, and Pinky, Elmyra and the Brain along with Looney Tunes shorts and segments from Tiny Toon Adventures and The Sylvester & Tweety Mysteries. However, when Kids' WB! started running Pokemon on Saturday mornings, The Big Cartoonie Show was shortened down to a half-hour show and only showed segments from Animaniacs and Pinky, Elmyra and the Brain (several of which had not aired before).
At the start of the 1999-2000 season, the Animaniacs and Pinky and the Brain shows themselves were taken off of the weekday afternoon schedule, but remained on Kids' WB! in the form of the second season of The Big Cartoonie Show, now renamed The Cat & Bunny Warnernoonie Super Looney Big Cartoonie Show. The compilation show continued to air on Kids' WB!'s Saturday morning and weekday afternoon schedules until September 11, 2000, at which point the shows were taken off of Kids' WB! altogether.
Despite Animaniacs and Pinky and the Brain having been so prominent on the original Kids' WB! programming block in its early years, neither show was ever featured on the online Kids' WB! network.