The 2016 Disney version has it's own WMG page
For the 1967 animated Disney movie:
King Louie was a victim of animal smugglersIt would explain how an orangutan ended up in India. He was taken from his native home as a youngster, sold as an exotic pet, and then dumped in the jungle when he got too big. One of the reasons he wants to be man-like is so he can be accepted into the man village, even calling Mowgli "cousin", since there are no other orangutans around.
- Here's something that might count as a silver lining. He was absent from the 2003 sequel because conservation workers found him and sent him back to his homeland.
King Louie's name was self-chosen, and named after King Louis of FranceKing Louie knows that humans have so many wonderful technologies (including fire, weapons, and many others), and stronger armies than a monkey band, and this is why he wants to be like them. And he knows the difference between the European humans and those who are native to India, and knows that Europeans have the best technology and armies. So the fact that he has a European name is explained by him naming himself after the most powerful kind of human, a European king. He knows nothing about the actual biography of King Louis (and he couldn't tell the difference between France and the England where the colonists come from). He just knows that "the king, in the land where the white men come from, is named King Louis."
Hathi was tasked by the Jungle's elephants to keep rogue males out of troubleIn real life, elephant herds are led by a matriarch, not a male. Males are usually solitary and only join the female herds to breed. However, Hathi is shown very clearly to be the leader of a male-only group, with the sole exception of his mate Winnifred. Hathi is also heavily implied to have been a war elephant at some point, if his half-forgotten anecdotes and British accent and mannerisms are anything to go by. It is likely that Hathi escaped into the jungle (or was released as a reward for his services), and once there, he found himself without anything to do. It is possible that he tried to join a normal, wild herd, but he annoyed the other elephants so much that the matriarchs decided to get rid of him by tasking him with recruiting all solitary and rogue male elephants and keep them constantly busy so they wouldn´t cause trouble by harassing the females OR attacking or raiding man's villages and crops, which of course could only result in trouble for everyone in the Jungle.Winnifred was probably assigned to keep an eye on him and report to the wild matriarchs regularly, but she ended up falling for Hathi and becoming his mate (although she obviously would rather be the leader herself).
Hathi is secretly the Mad Elephant of MandlaKipling's original story speaks in passing of a mad elephant that went on killing rampages and caused heavy monetary losses to the Indian government. Since Hathi appears to have been a war elephant, he may actually suffer from PTSD and go crazy sometimes, which may be why the other elephants have no choice but to obey him and suffer his repetitive stories, lest he go crazy on them. Hathi himself would have no idea of this, considering his terrible memory...
Jacala the crocodile killed Mowgli's parentsMowgli is found in a broken canoe by the river shore with no adult at sight. It is a possibility that his parents or whoever he was traveling with was killed by a wild animal; the state of the canoe would point at Jacala the crocodile (mentioned by Kipling but unseen in the movie) as a very likely responsible. Alternatively it may have been Shere Khan, but it would've been odd for him to leave Mowgli behind.
For the Kipling stories:
Tabaqui doesn't really have rabies.He's one of the least-formidable carnivores in the jungle, and he hangs around with animals much stronger and more aggressively-predatory than himself. The only way he can ensure that none of them try to bully, kill, or eat him is to fake being rabid so they won't risk infection.
- Very likely considering that if he was truly rabid, he wouldn´t have been alive by the time Mowgli is a teenager.