It was 1992. Or maybe 1989, if you were in Japan. Kids walked into theaters expecting a standard cartoon and walked out having experienced a fever dream of high-budget animation and genuine nightmare fuel. Little Nemo: Adventures in Slumberland is one of those movies that feels like a collective hallucination. But the Little Nemo: Adventures in Slumberland cast is where things get truly fascinating. You’ve got a mix of Hollywood legends, child stars of the era, and voice acting royalty all trying to make sense of a project that spent a decade in "development hell."
The movie didn't just happen. It was a brutal tug-of-war between Japanese visionaries and American writers. At one point, even Hayao Miyazaki was involved before he walked away because he couldn't stand the script. Honestly? Looking at the final product, you can see the scars of that struggle. It’s beautiful, messy, and the voice acting is the glue holding the whole thing together.
The Boy in the Pajamas: Gabriel Damon as Nemo
Gabriel Damon was the "it" kid for raspy-voiced protagonists back then. Before he was Nemo, he was the voice of Littlefoot in The Land Before Time. You know that specific, vulnerable-but-brave tone? That was his trademark.
In Little Nemo, he basically spends eighty percent of the movie screaming as he falls through the air. It’s a lot of work. He brings a genuine sense of wonder to the role, which is hard when you're recording lines for a character who is essentially a blank slate for the audience to project onto. Interestingly, Damon didn't just do voice work. He was a legit child actor in live-action too. If you grew up in the 90s, you probably recognize him as the "bad kid" Hob in RoboCop 2 or Spot Conlon from Newsies.
The contrast is wild. One day he’s a drug-dealing kid criminal in a dystopian Detroit; the next, he’s a wide-eyed dreamer in a nightshirt. That’s range.
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Mickey Rooney as the Mischievous Flip
If Nemo is the heart of the movie, Flip is the chaotic energy that keeps it from getting too sweet. And who else could they have cast but Mickey Rooney?
By 1989, Rooney was a Hollywood institution. He’d been acting since the silent film era. He brought this raspy, vaudevillian, cigar-chomping energy to Flip that made the character instantly iconic. Flip isn't exactly a "good guy" for most of the movie—he’s a troublemaker, a gambler, and the guy who tricks Nemo into opening the Nightmare Door.
Rooney’s performance is loud. It’s abrasive. It’s exactly what a green-faced clown with a "Keep Out" sign on his hat needs to sound like. There’s a specific kind of old-school showmanship in his delivery that you just don't hear in modern voice acting. It’s not "natural." It’s a performance.
The Supporting Legends: From Star Trek to Disney
The rest of the Little Nemo: Adventures in Slumberland cast is basically a "Who's Who" of character actors.
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- René Auberjonois (Professor Genius): Long before he was Odo on Star Trek: Deep Space Nine, or the chef in The Little Mermaid singing about "Les Poissons," Auberjonois played the frantic, etiquette-obsessed Professor Genius. He’s the one who has to explain the rules of Slumberland, and he does it with a frantic, theatrical energy.
- Laura Mooney (Princess Camille): She was a prolific child actor at the time, appearing in Saved by the Bell and Murphy Brown. As Camille, she provided the necessary "royal" foil to Nemo’s suburban-kid vibe.
- Danny Mann (Icarus): The flying squirrel who only speaks in squeaks and broken English? That’s Danny Mann. He’s a legend in the voice acting world, having voiced characters in everything from FernGully to Pocahontas. He actually stayed on for both the English and Japanese versions (partially), which is a rarity.
- Bernard Erhard (King Morpheus): He gave the King that booming, Santa-Claus-gone-noble presence.
- Bill Martin (The Nightmare King): If you had nightmares about the black sludge after watching this, thank Bill Martin. His voice for the Nightmare King was deep, distorted, and genuinely terrifying for a G-rated movie.
Why This Cast Worked (When the Movie Almost Didn't)
The production of this film was a disaster behind the scenes. It took nearly 15 years to get made. The producers went through Ray Bradbury, Chris Columbus, and even George Lucas at various points. By the time they actually started recording the English dub, the animation style was a weird hybrid of 80s anime and classic Disney.
The cast had to bridge that gap.
The Japanese cast featured heavy hitters like Takuma Gōno (Nemo) and Chikao Ōtsuka (Flip), but the American version is what most people remember. The English script, co-written by Chris Columbus (Home Alone, Harry Potter), leans heavily into the "American Kid in a Strange Land" trope.
The Weird Connection to The Sherman Brothers
You can't talk about the cast without mentioning the music. The legendary Sherman Brothers—the guys who wrote the music for Mary Poppins and The Jungle Book—wrote the songs for Little Nemo.
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Hearing Gabriel Damon and René Auberjonois sing "Etiquette" is a trip. It’s this incredibly polished, Disney-esque musical number inside a movie that otherwise feels like an experimental Japanese art project. The cast had to handle the tonal shifts from "silly song about manners" to "running for your life from a giant cloud of sentient oil."
The Japanese Voice Talent: A Different Flavor
While the American cast is full of Hollywood names, the Japanese Little Nemo: Adventures in Slumberland cast (the original 1989 release) is a goldmine for anime fans.
Chikao Ōtsuka, who voiced Flip, was a massive deal in Japan. He was the voice of Gold Roger in One Piece and Captain Hook in Kingdom Hearts. His take on Flip was a bit more grounded in the "trickster" archetype compared to Rooney's "vaudeville" take.
What Happened to the Cast?
Most of the actors went on to massive careers, while some moved away from the spotlight.
- Gabriel Damon eventually retired from acting and became a real estate broker. He occasionally pops up at conventions to talk about The Land Before Time and Nemo.
- Mickey Rooney kept working right up until his death in 2014. He was the ultimate "workhorse" of Hollywood.
- René Auberjonois became a sci-fi icon and a beloved stage actor before passing in 2019.
- Danny Mann is still very much active in the industry, providing voices for modern hits like Despicable Me.
Actionable Insights: How to Watch It Today
If you're looking to revisit Slumberland or show it to your kids for the first time, here is how you should handle it.
- Watch the Remaster: Look for the Discotek Media Blu-ray. The colors are way more vibrant than the old VHS tapes we grew up with.
- Listen for the "Nemo" Squeak: Pay attention to Gabriel Damon's voice. You’ll hear the exact same inflections he used for Littlefoot. It’s a fun "Easter Egg" for 80s/90s animation buffs.
- Check out the Pilot Films: Before the final movie was made, several "pilot" shorts were created. One was directed by Yoshifumi Kondo (who worked on Whisper of the Heart) and another by Osamu Dezaki. They are available on YouTube and look significantly different—and in some ways better—than the final film.
- Skip the Netflix Live-Action Version (Maybe): There was a 2022 Netflix movie called Slumberland starring Jason Momoa as Flip. Just a heads up: it’s barely related to the 1989/1992 animated classic. If you want the real experience, stick to the original cast.
The magic of Little Nemo isn't just in the billion-dollar animation (which was a lot for the time); it's in the voices. They brought a human touch to a world that was constantly shifting and melting. Whether it was Rooney's growl or Damon's gasps of wonder, that cast made Slumberland feel like a place you could actually visit—as long as you didn't forget your pajamas.