The Goodfeathers, a satire of the Warner Brothers film Goodfellas (1990) were made to reflect the personalities of the film's main stars. Bobby the blue pigeon is meant to be Robert De Niro, Pesto the purple pigeon is meant to be Joe Pesci, and Squit the gray pigeon is meant to be Ray Liotta. in addition, The God Pigeon is meant to be Marlo Brando from The Godfather (1972).
During the theme song the characters proudly anounce that "We have pay or play contracts". This is a Hollywood term meaning the performer is paid whether or not he plays - this was a big deal in the days of contract studio players.
The Pinky and the Brain sketch titled, "Yes, Always", was taken virtually word for word from a recording of Orson Welles doing a commercial and berating the director and his suggestions for Welles' delivery. In this recording, Welles uses some rather bad language, which was changed for the sketch.
After a few seasons the line "Bill Clinton plays the sax" was removed from the opening credits. It was briefly replaced with the line "We have wisecracks by the stacks", but it soon gave way to "We pay tons of income tax".
The water tower where the Warners live and many other features of the Warner lot are rather accurate representations of the Warner Studios lot in Burbank California. (Although, the real water tower is all gold, not red on top.)
Writer/producer Sherri Stoner created Slappy the Squirrel after her friend and fellow writer John P. McCann made fun of her career playing troubled teenagers. McCann said she'll be playing troubled teens into her fifties. So she went the other direction, and created an older person acting like a teenager.
The show, during its initial run, was more popular with teenagers and adults, than children. This became a problem as The WB always placed it inside of their "Kids WB" programming block, which eventually caused the series to be canceled, as sponsors of the block felt uneasy about footing the bill for an audience they couldn't sell products to.
In the opening of the Pinky and The Brain segments, Brain writes "THX=1138" on the blackboard. This is a reference to THX 1138 (1971), written and directed by George Lucas. Lucas is a near life-long best friend of Steven Spielberg, Executive Producer for Animaniacs.
The Animaniacs theme is in part a satire of "This Is It", the theme song from The Bugs Bunny Show (1960). For example, Bugs and company sing "No more nursing, rehearsing a part. We know every part by heart." The Animaniacs sing, "The writer's flipped. We have no script. Why bother to rehearse?"
When Tom Ruegger created Buster Bunny for Tiny Toon Adventures (1990) he wanted to create a catch phrase (to parallel Bugs' "What's up, Doc?"). All he could think of was the old vaudeville standby "Hello, nurse!" but that made no sense for the character. Now the phrase is used by Yakko and Wakko when greeting Dr. Scratchansniff's attractive assistant or any desirable woman.
Many different last lines were used for the show's theme song. The most frequent was "Here's the show's name-y", but others include "Shirley MacLaine-y", "Citizen Kane (1941)-y", "Tarzan and Jane-y", "Pinky and the Brain (1995)-ey", "Come back Shane (1953)-y," "Where's Lon Chaney?" and "Dana Delany." (When shown on Nicktoons TV, however, the line is always "Nickilaney").
The Warner siblings are based in a roundabout way on senior producer Tom Ruegger's three real-life children. Originally, they were going to be ducks named Yakki, Smakki and Wakki, but this idea was canned (it was thought to be too similar to DuckTales (1987)), and the three were changed into platypi, then into Bosko-like inkblots. Along the way, they gained a female friend; finally, Yakki became Yakko, Smakki and Wakki were combined into Wakko, and the female friend was named Dot and made their sister.
Slappy Squirrel was originally an older version of Screwy Squirrel, but the creators couldn't get the rights. Sherri Stoner liked the idea of an aged cartoon character because an aged cartoon star would know the secrets of other cartoons and "have the dirt on [them]"
The series was made with a higher production value than standard television animation; the show had a higher cel count than most TV cartoons. The characters often move fluidly, and do not regularly stand still and speak, as in other television cartoons.
Sherri Stoner invented Dot's full name (Princess Angelina Contessa Louisa Francesca Banana Fanna Bo Besca III) using the song "The Name Game" by Shirley Ellis and also patterned it after Pippi Longstocking's full name: Pippilotta Delicatessa Windowshade Mackrelmint Ephraim's Daughter Longstocking.
Throughout the series, Dot Warner's voice gets slightly deeper each episode, and is also evident in the movie Animaniacs: Wakko's Wish (1999). This was Tress MacNeille's idea, as she thought it would be a good idea to have the Warners age, and have Dot go through puberty.
Yakko appeared as an inflatable balloon display on top of the water tower in Burbank in real life, this was in promotion of the show before it was released. However, when Bob Daley, who ran the studio at the time, saw the balloon, he thought that for some reason, Mickey Mouse was sitting on top of the tower and he requested it to be removed. It was removed but not before Paul Rugg took a photo of the balloon.
One of the regulars (Ralph the Guard) was a recurring character in the later episodes of Tiny Toon Adventures (1990); also, several other characters have made cameo appearances, and the theme song from it shows up occasionally as well. See also Pinky, Elmyra & the Brain (1998).
At one point, the introduction of a fourth Warner, named Lakko, was considered. He would have been the straight man of the team, modeled after Zeppo Marx. The Animaniacs film for which he was developed, "Wandering Warners We," never made it past the development stage.
In a "Animaniacs" tribute by Doug Walker (The Nostalgia Critic), Walker, who had done a video listing 11 of the "naughtiest" moments in the show, was curious as to how the writers were able to get so many "naughty" jokes past the censors (such as the famed fingerprints" joke). The consensus from writers Tom Ruegger, Sheri Stoner, Paul Rugg and John P. McCann was essentially "We have no idea."