Every time there's a new Disney movie, there are new fan theories. I imagine you've received wind of some of Zootopia's new set; for instance, the theory that Nick Wilde might be descended from Robin Hood. An intriguing suggestion, but to even consider it, you have to prove it's possible — that Nick Wilde and Robin Hood even exist in the same universe. The possibility grew on me, leading me to more questions, until I wanted to know what other Disney stories might click with Zootopia. This is where that train of thought led me.
First off, let's lay out some ground rules: 1) I'm not trying to prove that anything is necessarily so, only that it's completely possible within the confines of the laws defined by these story worlds; that's the fun of fan theories. 2) I'm going to assume that you've seen Zootopia, but even if you've been living under a rock, I won't be spoiling much in terms of story, so you can read on safely. However, you'll have to understand two basics about Zootopia: Tt's a world full of anthropomorphic animals (so, furries), and the movie's outstanding theme is racism and defying stereotypes.
Ready? Good. Let's go wild. After all, it's a pretty big world.
Could Robin Hood Exist In The Zootopia World?
Up front, one question makes or break this possibility: Have birds and reptiles evolved in the world of Zootopia?
They definitely existed in Robin Hood. So for this theory to work, there has to be some other city, somewhere outside of Zootopia, where anthropomorphic reptiles and birds exist. Is this possible? I'm going to say yes, yes it is. And it's possible to justify their absence in Zootopia.
We see a lot of racism in Zootopia on various levels — significantly, predator versus prey — but even just among the prey, we see rhinos and buffalo discriminating against a rabbit. It's very probable that if there's this much racism among mammals, they might stick to themselves, and segregate birds and reptiles (the warm-blooded versus the cold-blooded). In a way, this even seems fair, and it comes down to biology. The difference in the infrastructural needs of evolved birds, reptiles, and mammals is pretty crazy.
It took enough work to divide the city into sixteen districts to support different mammals' environmental needs, not to mention creating at least one city-within-a-city for housing Zootopia's smallest denizens (wherein the mice probably treated shrews and moles as second-class citizens).
Somebody will read this and think, "The filmmakers just needed to draw the line somewhere, they said so themselves." So true. And this argument against this theory actually works in its favor. If it was too complicated for the filmmakers to conceive of a city suited to meeting the needs of the full spectrum of mammals as well as reptiles and birds, then it would be too hard for the animals that inhabit the Zootopia world, as well. It's not that the filmmakers couldn't find room for more characters from other biological classes; it's that they couldn't make their world find room for them.
You could also argue that the lack of songbirds in Bunny Borough, or lizards and snakes in the rainforest district, suggests that these animals must have evolved and moved elsewhere.
That's the case from the Zootopia side, but there's more to be said about how Zootopia fits into the world Robin Hood created.
When Robin Hood was made, its world was designed to mimic the natural order of the animal kingdom; they put predators in power, and class in Nottingham went down depending on how big you were and what you ate. We have lions for royalty, a badger for a sheriff, and herbivorous peasants. What's interesting to note, however, is that what we see of birds and reptiles would appear to put them in an even lower class than any of the mammals. We have an owl beggar, a rooster minstrel (i.e. a hobo), a chicken lady-in-waiting, and vultures and crocodiles as guards and soldiers (though there were mammal soldiers, they seemed to be generally higher-ranking). It's easy, then, to imagine the world of Nottingham developing, over several hundred years, into the world described by this theory.
Back to Zootopia for a moment to address one more obstacle: In a world where all the prey is evolved, what can the carnivores eat? Bugs, sure — they're highly nutritious and there's plenty of 'em, but let's face it, Mayor Lionheart would need a lot of ants to fill his belly. Fish? I can't confirm it, but the rumors out there that there was a fish stand somewhere in the movie, and this makes sense. Animals tend to evolve out of the sea, after all, and when it's survival of the fittest, someone has to get left behind. Sorry, Nemo.
That said, in the Zootopia world — where mammals are definitely evolved — there can't be much doubt that somewhere in the sea there's an Atlantis built by evolved dolphins and whales. I want to see the fanfics now, preferably starring narwhals. But I digress. Let's continue.
Does The Sky Fall On Chicken Little? Is Mickey Mouse Confined To The Cubhouse?
So here's the deal: Chicken Little and Mickey Mouse could very possibly exist in the same world, but it's not so easy to fit them into Zootopia. One reason is simply proportion — Mickey, a mouse, is the same size as Donald, a duck, which obviously doesn't jive in Zootopia. The other reason is that Chicken Little and Mickey Mouse seem to exist in a universe with a complete utopian lack of racism. We'll address this one first.
In Chicken Little, you see mammals and birds all living together. (Not to mention a fish, though just how evolved he actually is remains unclear.) For that to fit into this theory, the only excuse would be to chock it up to regionalism, a hard pill to swallow when you consider Chicken Little's barnyard home resembles the American South. I'm sure you can see the obstacle to calling it a racism-free utopian region.
Proportion is less of a problem, but it could really swing either way. Certainly they don't attempt the same accuracy as Zootopia (which isn't perfect either), but they're not quite as carelessly sized as the Mickey Mouse gang. Chicken Little doesn't have anywhere near the same level of world development as Zootopia, or as much source material to draw evidence from. It's a virtually lawless world which has no place in the well-ordered universe defined in Zootopia. I'm going to have to reject it from the theory and, to be honest, maybe this movie is better left forgotten, anyway.
Moving on to Mickey Mouse, we have a case all its own. It's impossible to make a cohesive argument for or against because there's simply no set canon. Between Mickey, Donald, and Goofy and all their separate stories and spin-offs, in movies like A Goofy Movie and television series like DuckTales and Chip 'n Dale Rescue Rangers, we've seen a multitude of versions of the characters and the world they inhabit. Sometimes they even include humans. Possibly worse, they include distinctly un-evolved animals, such as Pluto. There's not much that can be done to explain why the classic Goofy versus Pluto paradox could exist in this theory.
But rather than reject Mickey Mouse completely, I simply propose a new headcanon: Now properly proportioned, Mickey, Donald, and Goofy live in Duckburg and its suburb, Mouseton. They're close friends, and even though Mickey is in constant danger of being stepped on during one of Donald's tantrums or because of Goofy's clumsiness, they still manage to forge an unbreakable bond of friendship, even in the face of adversity (and diversity). Truly inspiring.
As far as Robin Hood is concerned, I'm convinced that it could coexist with the world Zootopia showed us. And even though Chicken Little isn't looking too good, Mickey Mouse and his friends could fit right in with a few changes.
In the end, theories are just theories. We don't call the shots, the filmmakers do. But sometimes fan theories end up entering the official canon, or at least the popular headcanon. That's the fun of being a part of any fandom — you get to share your ideas and interpretations for other people to add to their understanding of the story.