Evolution. It's what has changed our species from unsophisticated, heathen apes to glorious, smartphone-using apes, and I can't wait to see what it will do next. Three arms? Please let it be three arms.
It's also pretty prevalent in animals, even the animated ones. Go ahead. Look at two of the Disney films that are set before The Jungle Book: Snow White and Hercules. Animals don't talk. They don't impart a lick of wisdom onto the clueless human protagonists. And Iago from Aladdin or Archimedes from Sword In The Stone, both movies that predate The Jungle Book as well, don't count, because they're obviously enchanted by the magicians that they hang out with. Whenever direct exposure to magic is involved, you can attribute any abnormal intelligence to enchantment. If all birds could talk, then that flamingo would've just asked Iago, "You tryin' to fuck, lady bird?" instead of just panting his heart out.
So why is it that I specifically mentioned The Jungle Book? Well, because if it weren't for Mowgli, there would be no communication between animals and humans and no whimsical stories that would teach generations of children to look at their non-talking pets with disappointment. Here's the timeline based on the years that Disney animations take place before Jungle Book:
The Animals Cannot Speak (Pre-Jungle Book Era)
270 B.C.: Hercules (no talking animals)
500s: Mulan (no talking animals)
700s: Sword In The Stone (only a magician's talking owl -- which is probably enchanted)
900s: Aladdin (no talking animals except Iago -- but he may be enchanted by Jafar. He even pretends to be a real parrot around the Sultan at first)
1500: Sleeping Beauty (no talking animals)
1550s: Snow White And The Seven Dwarfs (no talking animals)
1750-1795: Beauty And The Beast (no talking animals)
1607: Pocahontas (no talking animals)
1840s: Tangled (no talking animals)
1840s: Frozen (no talking animals)
1880s: Little Mermaid (animals don't communicate with humans, just mermaids, who are half-fish)
1880s: Jungle Book (only Mowgli can talk to the animals)
Why Is Mowgli So Important?
Remember King Louie singing an entire song about wanting to walk and talk like humans? This should seem weird to anyone, because he's dancing and singing like a human, so why on Earth would he need fire? Well, his and every other animals' speech is strictly for the viewers' benefit. It's basically there so that no one would have to painstakingly subtitle the roars and growls. In actuality, only Mowgli can understand any of these creatures. That's what makes Mowgli so special. King Louie knows that Mowgli is all Beastmastered up and wants to take advantage of this gift and finally bridge the gap between man and beast. The only way he can do this is if Mowgli shows him how to make fire.
I wanna be a man, man-cub
And stroll right into town
And be just like the other men
I'm tired of monkeyin' around!
What I desire is man's red fire
To make my dream come true!
Being that King Louie knows of fire's existence and knows that humans are capable of making it, wouldn't it have been easier if Louie or one of his monkey lackeys just followed some humans and watched them make fire from afar instead of pursuing Mowgli? Well, it's not that simple. The ability Mowgli holds allows him to bestow clear understanding, which is why he can openly talk to each and every species in the jungle.
This is a once-in-a-lifetime opportunity, and King Louie knows it. Mowgli is the key to evolution.
Mowgli Is The Animals' Prometheus
In the legend of Prometheus, Zeus withheld fire from prehistoric man, and they were "unenlightened," because Zeus is a giant dick. All of man's Hot Pockets were uncooked, and they were fucking miserable because of it. It wasn't until Prometheus delivered fire to mankind that they became "enlightened" and began to walk upright. We're talking about evolution here.
At the climax of the first film, Mowgli reveals fire to the creatures in an effort to keep Shere Khan away.
The Jungle Book
What could go wrong?
And then everything changes. Just like mankind in the Prometheus legend, the animals gain intelligence and become "enlightened." It's like Walt Disney's version of 2001: A Space Odyssey. After the events of the first film, the animals are then able to communicate with other humans (as seen in The Jungle Book 2, where Mowgli's friend is able to communicate directly with Baloo), a fact that we have to tell you outright because The Jungle Book 2 didn't exactly blow up the box office.
The Jungle Book
Look what you made us do!
Years later, in Disney's TaleSpin, Baloo, Shere Khan, and King Louie move out of the jungle and move into an intelligent animal utopia called Cape Suzette. It's definitely a positive outcome, since before TaleSpin if your kid asked, "What happened after The Jungle Book, mommy?" all you could say was, "Poaching, sweetheart." And you can tell that these may be the same creatures, as their hands are still very paw-like and their "thumbs" are not fully formed. They haven't gotten the full Moreau treatment yet. Compared to the other Disney afternoon cartoons of the time (DuckTales, Chip 'N Dale Rescue Rangers, etc.), TaleSpin looks like it takes place much earlier (it's somewhere in the 1910s, according to Disney Adventures magazines). Cape Suzette might just be the first animal-only city in the world. This all makes sense, as Mowgli enlightened most of its citizens.
The Jungle Book
The Animals Begin To Talk (Concurrent Or Post-Jungle Book Era)
1880s: Jungle Book 2 (Shanti can understand Baloo now too)
1880s: Alice In Wonderland (enlightened animals only happen in a dream but still possibly exist)
1880s: Tarzan (enlightened animals only communicate with Tarzan)
1880s: Legend Of Tarzan (enlightened animals openly communicate with Jane and the Professor)
1880s: Pinocchio (enlightened fox, cat, and cricket that openly communicate with humans)
1880s: Cinderella (enlightened mice communicate with Cinderella)
1900s: The Fox And The Hound (enlightened animals purposely hide their intelligence from humans)
1909: Lady And The Tramp (enlightened animals purposely hide their intelligence from humans)
1910: TaleSpin (enlightened animals live in their own utopia)
1910: The Aristocats (enlightened animals purposely hide their intelligence from humans)
Not to be confused with The Aristocrats. Very important distinction.
1916-1926: Princess And The Frog (enlightened crocs and frogs communicate with few humans)
1941: Dumbo (enlightened mouse talks to sleeping human; sleeping human understands mouse)
It seems that in this stage of the world, animals who gained intelligence kept their intelligence secret for the most part (as seen in The Rescuers, Cinderella, etc.). In fact, Tarzan thinks he can talk to animals, but it turns out they're actually only talking to him (which is why he can later speak clearly to the humans). Further proof of this is that in The Legend Of Tarzan animated series, the animals openly talk to the other humans, meaning that they were simply hiding their intelligence.
This agenda to keep their intelligence secret was evident as far back as Jungle Book 2, where the rest of the animals saw Baloo's attempts to communicate with humans as a threat to their kind. Needless to say, his attempt was met with great resistance:
And even when they do go further than simple communication and start doing business with humans, it's always nefarious, underground business. The fox and the cat in Pinocchio are total pieces of shit who deal in the kidnapped-children market. They're on the absolute fringe of society. It really doesn't get fringier than "sell kids to be tortured on an island."