Looney Tunes

Looney Tunes is an American animated comedy theatrical short film series produced by Warner Brothers.

Throughout the years, both Hanna-Barbera and Looney Tunes have made several references to one another.

Blast-Off Buzzard

 * The Blast-Off Buzzard shorts themselves share similarities to the Wile E. Coyote and Road Runner theatrical shorts.

Fantastic Max

 * At the end of the episode, "Movie Star Max," there's a sequence where Max pops out to tell the viewers, "Th-th-that's it, folks!"

Flintstones

 * In the Baby Looney Tunes episode, "The Wheel Deal," the Flintmobile makes a cameo when Bugs and the others are trying to make a brand new bike to fit Tweety's size.
 * In celebration of Warner Bros.' 100th anniversary, they produced a special short which reimagined Looney Tunes characters taking a group photo together in Bedrock, but this is spoiled by Daffy who comes dressed as Fred and then Bamm-Bamm, even though Bugs and Sylvester were already covering them respectively.

Hokey Wolf

 * The Hokey Wolf short, "Robot Plot," was likely inspired by the Looney Tunes short, Robot Rabbit.

Scooby-Doo

 * Scooby and Shaggy make cameos at the WB cafeteria in Looney Tunes: Back in Action, where they are voiced by Frank Welker and Casey Kasem respectively.
 * Wile E. Coyote and Road Runner make cameo appearances in the What's New, Scooby-Doo? episode, "New Mexico, Old Monster," with the Road Runner's voice being from an archival recording of Paul Julian.
 * Tweety also makes a cameo in Avery's bird watching guidebook.
 * For Warner Bros.' 100th anniversary, they teamed up with Funko to release Looney Tunes Pops with a Scooby-Doo motif. A crossover short was made for Cartoon Network's Acme Fools month-long marathon, based on the same Funko Pop renderings with the Looney Tunes cast as Mystery Inc. attempting to unmask the Ghost of Mr. Hyde.

Other

 * The concept for the unrealized project, Toing Tiger likely became the character Cool Cat.