Kaa

First introduced in the story "Kaa's Hunting" in The Jungle Book, Kaa is a huge and powerful snake, more than 100 years old and still in his prime. In "Kaa's Hunting", Bagheera and Baloo enlist Kaa's help to rescue Mowgli when the man-cub is kidnapped by Bandar-log (monkeys) and taken to an abandoned human city called the Cold Lairs. Kaa breaks down the wall of the building in which Mowgli is imprisoned and uses his serpentine hypnosis to draw the monkeys toward his waiting jaws. Bagheera and Baloo are also hypnotized, but Mowgli is immune because he is human and breaks the spell on his friends.

In The Second Jungle Book, Kaa appears in the first half of the story "The King's Ankus". After Kaa and Mowgli spend some time relaxing, bathing and wrestling, Kaa persuades Mowgli to visit a treasure chamber guarded by an old cobra beneath the same Cold Lairs. The cobra tries to kill Mowgli but its venom has dried up. Mowgli takes a jeweled item away as a souvenir, not realizing the trouble it will cause them, and Kaa departs.

In "Red Dog", Mowgli asks Kaa for help when his wolf pack is threatened by rampaging dholes (the red dogs of the title). Kaa goes into a trance so that he can search his century-long memory for a stratagem to defeat the dogs:

For a long hour Mowgli lay back among the coils, while Kaa, his head motionless on the ground, thought of all that he had seen and known since the day he came from the egg.

The light seemed to go out of his eyes and leave them like stale opals, and now and again he made little stiff passes with his head, right and left, as though he were hunting in his sleep. Mowgli dozed quietly, for he knew that there is nothing like sleep before hunting, and he was trained to take it at any hour of the day or night. Then he felt Kaa's back grow bigger and broader below him as the huge python puffed himself out, hissing with the noise of a sword drawn from a steel scabbard;

"I have seen all the dead seasons," Kaa said at last, "and the great trees and the old elephants, and the rocks that were bare and sharp-pointed ere the moss grew. Art thou still alive, Manling?"

With Kaa's help Mowgli tricks the dholes into attacking prematurely. Kaa takes no part in the resulting battle (obliquely citing his loyalty to the boy rather than to the wolves, who often caused Mowgli grief) but Mowgli and the wolves finally kill all the dholes, though not without grievous losses.

In "The Spring Running", as the teenage Mowgli reluctantly prepares to leave the jungle for the last time, Kaa tells Mowgli that "it is hard to cast the skin," but Mowgli knows he must cast the skin of his old life in order to grow a new one. Kaa, Baloo and Bagheera sing for Mowgli in "The Outsong", a poem and the ending of "The Spring Running".

• In the 1967 Adventures of Mowgli Soviet cartoons, Kaa was voiced by Vladimir Ushakov in the Russian version, by Sam Elliott in the English dub, and by Adriano Celentano in the Italian dub. This version of the serpent, like the cartoons in general, is faithful to the original books.
• In the 1989 Japanese anime series Jungle Book Shōnen Mowgli, Kaa's personality is closer to the books than the Disney series. He is voiced by Keaton Yamada in the Japanese and Terrence Scammell in the English dub.
• A snake-like character resembling Kaa made a cameo during the final scene of Who Framed Roger Rabbit (1988) with the other Disney characters.
• Kaa also made an appearance in the 1997 live-action film The Second Jungle Book: Mowgli & Baloo. He appears as the snake charmer Karait's pet female python.
• In the 2010 CGI animated television series, Kaa is given a more ferocious personality than in the books, but at the same time he is friends and allies with Mowgli, Bagheera, and Baloo.
• In Mowgli: Legend of the Jungle, Kaa is a gigantic female Indian python with a calm but intimidating personality. She is a seer and is bigger than her 2016 counterpart with darker green and lighter yellow scales. She has more human facial features and full puffy lips. She is voiced by Cate Blanchett. This version is closer to the Kipling books, being a seer who takes a mentor-like role toward Mowgli and even saving his life at one point in the film.
• In the 2022 short The Simpsons: Welcome to the Club Kaa is one of the Disney villains meeting Lisa Simpson, being voiced by Dawnn Lewis. This was the very first time the character appears in animation ever since The Jungle Book 2. In the end credits he was shown hypnotizing Homer Simpson in his coils.