The characters were conceived on Animaniacs by the producer, Tom Ruegger, and one of the writers, Peter Hastings. Hastings wrote or co-wrote many of the pair's cartoons on Animaniacs, and was considered sort of the unofficial creator of the characters, the guy who knew what they would or wouldn't do. (Though there were, apparently, some things he would have preferred they not do; Ruegger added a running gag about Brain hitting Pinky -- a slapstick bit to keep kids alert in the middle of expository dialogue scenes -- whereas Hastings always felt it would be funnier to have him threaten to hit his sidekick and never quite do it.) When the characters were spun off into their own series on the then-new WB network, Hastings was in charge of it, and he favored half-hour stories with more plot and satirical content than the Animaniacs segments. Hastings added some twists to make Brain a more sympathetic character; in the short Animaniacs he could rely on the natural sympathy that the audience gives to a frustrated Wile E. Coyote type of character, but to carry a whole show, he needed to display his own sympathetic qualities. One way to do that was to surround Brain with human characters who made him look good by comparison. In the first full-length Pinky and the Brain episode, Brain's plan to take over the world is complicated by a kill-crazy Cold War nut who thinks Pinky's trademark cry, "Narf," stands for "Nuclear Attack Readiness Formation." In the second episode, Brain joins the workforce as part of his plan, and finds himself facing craven corporate executives and unscrupulous lawyers. And in the first season's Christmas special, which won an Emmy, Brain actually breaks down and cries in a sentimental and not terribly convincing twist. But it did succeed in showing viewers that there was more to Brain than the try/fail formula. The most successful of these devices was the introduction of Brain's arch-enemy, Snowball (Roddy McDowall), another genetically altered animal who wants to take over the world for evil purposes, as opposed to Brain, who just thinks (correctly) that humans are really stupid and they'd be better off with him leading them.
The Emmy for the Christmas show was in the prime-time category, best animated series; it beat out "The Simpsons" among others. While "\Pinky and the Brain had been planned as a Saturday morning show and did in fact run on Saturday mornings, the WB decided to air the episodes in prime time as well. It seemed like a good idea; "Animaniacs" had a lot of popularity with adults, and the WB didn't have many good shows to fill its prime time schedule. The problem was that Pinky and the Brain wasn't really a sitcom, like The Simpsons; it had only two regular characters, the same basic plot setup every week, made use of Animaniacs-style cartoon violence that branded the thing as a "cartoon" in the eyes of prime-time viewers, and was as likely to do short segments as half-hour stories. It just didn't look or feel like a prime-time series, and the ratings, even by the standards of a tough time slot, were very poor.
The WB's initial idea was to leave Pinky and the Brain in its original form on Saturday mornings, but also commission new episodes, in a different style, for prime-time. Hastings explained in an internet post:
As P&B headed into its second prime-time season, the network wanted to push the show forward and get some new "prime-time" writers. They wanted to see more emotional plot lines, and a big community of characters (sorta like, what's that show? Oh yeah, The Simpsons) What they really wanted to see was a show that was a bit more like the rest of their family oriented shows with a broader appeal to more viewers. Here's a problem - Pinky and the Brain live a special life, they are special mice in a human world, they are not odd mice in a world populated with talking animals. They are trying to take over the world. NO ONE knows this (almost no one). Even though they constantly tell people, nobody ever believes it. And this is crucial to the charm and uniqueness of the show. PINKY AND THE BRAIN HAVE A SECRET. Only they know and we know. Lots of other characters can ruin this. Anyway, I'm babbling...to march forward...I hired several new writers. New prime-time scripts were written. They are good and funny, but they are not what they network wanted. They wanted something completely new. They like Pinky and the Brain, but they didn't care about taking over the world or Acme Labs or Infindibulators or taking over the world or working alone at night or giant dryers or fooling Bill Clinton or mechanical suits or taking over the world. They wanted to see emotional stories with relatable characters that would appeal to lots o' people. In the meantime, time is flying by and it's getting more and more difficult to get on the air in the fall. Therefore, the show was put back into development to see what we could come up with.
The "prime-time" staff of writers included people who had written for shows like The Simpsons and Duckman, plus a writer who would later go on to write for Buffy the Vampire Slayer, David Fury. But the show never made it back to prime time, and the prime-time writers were let go with only four scripts having been written, all of which were eventually produced for the Saturday morning show. It says something about how adult-friendly the WB TV cartoons were that scripts written for prime time, with sexual innuendoes and political humor, could fit into the Saturday morning format without anybody noticing. (Also, one of the prime-time writers, who had written for The Critic and The Simpsons, later described Hastings as "one of the most talented people I have ever worked with." Kricfalusi acolytes like Amid Amidi will often say that animation writers are just talentless hacks who couldn't get jobs in prime-time sitcoms, but with shows like Animaniacs and Pinky and the Brain, the level of talent and skill among the writers was often equal to that of a good prime-time staff.)
While producing new episodes for Saturday morning, Hastings was asked to develop a new prime-time series for Pinky and the Brain, one that would have more of a sitcom format. He wrote a pilot which was a "behind-the-scenes" story, where Pinky and the Brain are Hollywood stars, dealing with agents, producers, neighbors, relatives, and, yes, wives. The WB passed on the script (it was later adapted into a Saturday morning episode, "You'll Never Eat Food Pellets In This Town Again), and, perhaps realizing that the WB was becoming disenchanted with cartoons -- as I said in a previous post, the network's executives were running into trouble with advertisers because Pinky and the Brain and Animaniacs had insufficient appeal to very young children -- Hastings left WB Animation soon after.
The show didn't really suffer from Hastings' departure; in fact, it improved a bit. The staff, headed by writer-producer Charlie Howell, shook up the formula by doing things like introducing Pinky's family ("The Family That Narfs Together Poits Together"), putting them in a three-part adventure inspired in part by The Prisoner ("Brainwashed"), and even writing musical numbers (though this may have been done, in part, so the writers could get royalties). The show even spoofed the network's suggestion that they add more characters; an episode called "Pinky and the Brain and Larry" revamped the title song and the show to include a new character, Larry, who completely screwed up the formula by his total uselessness.
The show went on strong for 65 episodes, but when it was up for renewal, the WB finally insisted that a new character be added. Somehow -- the idea is variously attributed to Steven Spielberg or some guy in marketing -- it was decided to put the mice in a house occupied by Elmyra, the obnoxious animal-loving girl from Tiny Toon Adventures. The idea was so stupid that even the new lyrics for the title song mocked it:
Now Pinky and the Brain
Have a new domain.
It's what the network wants --
Why bother to complain?
The writing of Pinky, Elmyra and the Brain was not bad (the staff was led by John McCann of Freakazoid), and by the end of its thirteen-episode run it was starting to get pretty good despite the horrible premise. But, inevitably, the addition of Elmyra didn't help the show gain an audience with little kids, so the ratings didn't improve, and the show was cancelled. I think it has to rank as one of the worst "re-toolings" in TV history. But it did win anohter Emmy, this time for outstanding children's animated series.
Pinky and the Brain always seemed to be well-respected by the animators who worked on it, more so than Animaniacs or Freakazoid. I'm not really sure why; maybe it was because it won an Emmy, or maybe because it was perceived as being less subject to interference from "The Suits" than most cartoons (until the Elmyra re-tooling, there wasn't a lot of network meddling with the format). But really, one of the weaknesses of the show was that it relied so heavily on dialogue that there wasn't always much for the animators to do in terms of facial expressions or visual effects. The first season of Animaniacs had much more visual imagination (that included the early Pinky and the Brain cartoons, which had more atmosphere and more visual gags than most of the spinoff episodes). But Pinky and the Brain were generally seen as the best characters WB TV Animation had come up with; there was a bit of Ren and Stimpy in them initially, but they soon went past that, thanks partly to the writing -- which gave them all kinds of interesting quirks and catchphrases -- and partly to the voice acting of Maurice LaMarche (Brain) and Rob Paulsen (Pinky). LaMarche's voice for the Brain was partly based on his famous impression of Orson Welles, which he also did in the movie Ed Wood; Paulsen voiced Pinky as a happy cockney idiot out of a Carry On movie. Together they did a lot to establish the characters as interesting and sympathetic and unique; their dialogue exchanges were often hilarious, especially in the famed "Are you pondering what I'm pondering" exchanges:
BRAIN: Pinky, are you pondering what I'm pondering?
PINKY: I think so, Brain, but where are we going to find a duck and a hose at this hour?
BRAIN: Pinky, are you pondering what I'm pondering?
PINKY: I think so, Brain, but if Jimmy cracks corn and no one cares, why does he keep doing it?
Pinky and the Brain is still remembered fondly; Entertainment Weekly recently had a blurb asking for its release on DVD (there are no current plans, WB said, but it's under consideration), and of course it has been ripped off a number of times, most obviously by Family Guy, where the baby Stewie is sort of an unfunny version of the Brain. I still think that the first season of Animaniacs is the best thing that WB TV Animation did, but I also think that the Pinky and the Brain spinoff is the show that has the best chance of becoming a classic.