King Louie was a victim of animal smugglers
It 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 France
King 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 trouble
In 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 Mandla
Kipling'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 parents
Mowgli 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. Kaa has hypnotized Bagheera before.
He seems to be aware of Kaa’s Hypnotic Eyes and tried to avoid looking at them before Kaa succeeded in putting him in a trance. This does raise the question of why Kaa would have hypnotized him in the first place, especially since Kaa is hunting around in the jungle for easy prey. King Louie is a younger male
That would explain why he has no flanges or throat pouch, despite being a male orangutan. Shere Khan lost his parents to a gang of hunters
They killed his parents using guns and fire. That is why he has an extreme fear of those weapons and vengefully hates humans.