The Bandar-log first appear near the end of the song The Bare Necessities, spying on Mowgli. Shortly afterward, they abduct him, although Baloo tries to rescue him. The monkeys take Mowgli to their king at the ancient ruins. King Louie offers to let Mowgli stay in the Jungle if he can teach him (King Louie) how to make fire through the song I Wanna Be Like You. During the song, the monkeys dance with their king around the ruins until Baloo and Bagheera show up to rescue Mowgli. When King Louie dances with "a girl orangutan," he pats her on the back, revealing that it was actually Baloo in disguise. While Baloo and Bagheera rescue Mowgli, King Louie and his monkeys work to try to get Mowgli back. During the chase, a stone pillar is knocked out of place and the building it supports begins to collapse. Louie holds it up, Baloo tickles him and the monkeys come to help. They use a battering ram to knock Baloo out of the way. When hit, Baloo lurches forward, knocking Louie into another pillar, breaking it. Baloo leaves Louie to hold up the collapsing building. After Mowgli, Bagheera, and Baloo escape, King Louie and the monkeys are not seen for the rest of the movie.
Younger versions of the Bandar-log appear briefly in the Jungle Cubs opening, where they antagonized a young Hathi who climbed up a tree after being terrified of a mouse Kaa chased earlier by throwing bananas on him, until they got flung away somewhere by the tree. They also appeared in several episodes including "The Ape Who Would Be King" and "Tree For Two".
The Bandar-log appear at the scene where Baloo and Mowgli enter the ruins, greeting, and later dancing with them and other animals in the song W-I-L-D. After the song, Baloo tells them and the other animals about the Man Village.
In the 1994 live-action movie, the Bandar-log appear more as mischievous treasure thieves associated with King Louie (an orangutan again). One day, a monkey is seen stealing a bracelet from a boy raised by wolves named Mowgli, which belonged and was offered to him by Katherine "Kitty" Brydon in their childhood before Mowgli was separated from civilization along with his pet wolf, Grey Brother. The monkey then runs off with Mowgli and Grey Brother in pursuit until they reach an abandoned city inhabited by monkeys called "Monkey City."
After Mowgli (with Grey Brother told to wait outside) enters the city and into the treasure trove, the Bandar-log are seen gathering along with their "king," King Louie wearing King Louis XIV's crown. When Mowgli demands that King Louie returns his bracelet and the ape refuses, the ape summons his treasure guardian; Kaa the deadly python. The monkeys watch in shock as a battle ensues between the boy and the snake in the moat; ending with the boy triumphing by wounding the snake with a dagger he found with the treasure pile and winning. After Mowgli wins and stares at the monkeys, the monkeys start to fear him. King Louie admits defeat, returns the bracelet to Mowgli, and applauds him with the monkeys cheering over his victory.
Later on, when Captain Boone (the main villain of the film) and Kitty reach the treasure trove, King Louie and the monkeys watch in horror as Mowgli and Boone engage in a fierce sword fight. The battle ends with Mowgli wounding the evil soldier on the right arm with a dagger. The Bandar-log cheer for Mowgli's next victory and King Louie takes care of the rest by summoning Kaa again.
As Mowgli and Kitty leave the place and Boone stays to gather some loot since "the treasure only brings death," the monkeys continue screeching, chittering, and cheering. Then, when King Louie and the Bandar-log stop, Boone suspects this means something strange is about to happen. His suspicions are proven correct when Kaa surprises Boone from behind; causing him to fall into the moat. When Boone is underwater, dragged down by the weight of the treasure in his backpack, he notices a few skeletons of people whom Kaa had killed in the past. Boone joins them while screaming in terror when Kaa unexpectedly appears and strikes, thus killing him. The Bandar-log and King Louie are happy and cheer over Boone's death.
In the 2016 film, the Bandar-log are portrayed as various species of Indian primates (namely macaques, langurs, and Indian gibbon) rather than all being the same species of monkey. Unlike in the previous adaptations, their nature is more sinister. They kidnap Mowgli and present him to their leader, King Louie, who is a Gigantopithecus in this version, in order to learn the secret of the "red flower". Like in the 1994 live-action film, they do not speak. Their vocal effects were created by using sounds of chimps and gibbons in addition to human voice actors.
In the original Rudyard Kipling stories, the Bandar-log were much more sinister and had no leader. Their sinister nature is restored in the 2016 film.
An original draft by Bill Peet suggested that the Bandar-log retain their more sinister nature from the book, but be led by a bigger-sized Bandar-log "king," who had no tail. This idea was dropped when Peet left the Disney studio due to his dispute with Walt Disney, who felt that scene to be too dark for family audiences. The 2016 film, which in many ways is closer to Bill Peet's original draft, restores the sinister nature of the Bandar-log.
In Hindi, bandar means "monkey" (although specifically not Langur monkeys, but rather the Rhesus macaque) and log means "people," which translates as "monkey-people."
In the animated Disney movies and television shows, the Bandar-log are portrayed with prehensile tails, something lacked by Old World monkeys in real life.