Alibaba is a resourceful orangutan who manages to find food in the water. After studying the Teknisi and learning that they use water bottles as fish traps, Alibaba has become adept at raiding the traps to take the fish for himself.
The Bandit Boys are a group of five- and six-year-old males that formed in baby school. Known for being mischief makers, the group likes to engage in food fights and wrestling matches.
Donald, "the Apprentice," is a six-year-old male who came to Nyaru Menteng with Daisy. Though they were close in forest school, Donald becomes the sidekick of the larger Chen Chen, enabling him to live a mostly worry-free life. During the series, he falls victim to an unknown illness but is able to recover. Orangutan Outreach, an affiliate of the rescue group Borneo Orangutan Survival (BOS) Foundation, has reported that Donald has since died.
Mercury is one of the victims of the mysterious illness.
Milo is the one who caused Bonita's retreat to the comforting Papau.
Rocky fights with Milo for dominance when Hamlet leaves.
Saturnus is the island's smallest male and is constantly seeking attention and discovering ways to turn anything into a toy. His love of pranks earns him the nickname of "Clown."
Togar is one of the original bandit boys, but after falling victim to the strange illness that struck the island, his role in the society is shaken. When he returns to the island, he is hesitant and fearful but eventually finds his place again.
Barata is Oren's best friend.
Bertha is the island's biggest female. She catches the eye of Saturnus, the island's smallest male.
Bonita is a five-and-a-half-year-old female who tends to be independent and something of a loner. When the Bandit Boys bully her, she quickly loses her confidence and runs away crying. Bonita's mother was killed by poachers wanting to sell Bonita as a pet, but she was rescued and taken to the Nyaru Menteng Rescue Center, where she entered baby school.
Bule is a Palas Island Male who even impressed Daisy when she first saw him. Hamlet has tried to psych him out. He is bigger than Hamlet but a real gentle orangutan.
Cha Cha is a six-year-old female who first came to the Nyaru Menteng Rescue Center when she was 18 months old. She viewed Lone Droscher Nielsen as her surrogate mother and was initially devastated at being separated from her. Her refusal to adapt to the island causes Nielsen to question whether Cha Cha can be an independent orangutan; however, Cha Cha soon bonds with the more boisterous Daisy and comes to accept her new home.
Chakra is the male invader from Palas Island who attempts to steal a bunch of bananas but is defeated by Mogok.
Chen Chen is an eight-year-old male who is missing his left eye because of an accidental injury sustained while playing. Although Chen Chen is one of the largest and most dominant males on Orangutan Island, newcomer Hamlet has come to challenge his alpha position. However, in episode six he and Hamlet cooperate in raiding a boat.
Chilli appears in episode 1 of season 2 alongside Pickle and Peanut.
Compost is a six-year-old female who came to Nyaru Menteng on August 29, 2003, still basically wild. She lost one of her ears after receiving an electrical shock. Compost, who is named after famed wildlife photographer Alain Compost, is nicknamed "The Photographer."
Daisy is a feisty and determined six-year-old female who takes no prisoners. Daisy came to forest school with Donald. When Donald starts bonding with Chen Chen, Daisy becomes something of a tomboy and shows that she can hold her own in an altercation. Brave, determined, and sometimes rebellious, Daisy is the one of the island's best foragers. Showing she can also be gentle, Daisy befriends the less confident Cha Cha.
Guy is a Palas Island male who mostly hangs out with Manisa.
Hamlet, called the "Intruder," is a 10-year-old male who escapes from the nearby Palas Island to make his home on Orangutan Island. In his first appearance on the show, he kidnaps Jasmine. However, despite this rude introduction, his five years of experience in the wild enables him to help the less experienced newcomers survive their first rainy season. Towards the end of season 1, Hamlet is deposed by Reno and then builds a relationship with Papau. Eventually Hamlet regains his position.
Hardi is a newborn baby who appears with his mother, Kiki, in season 2.
Hercules is a 20-year-old male. He is more aggressive than other adult orangutans on Orangutan Island.
Jasmine is a darker-colored, six-year-old female who is popular with the young males on the island, earning her the nickname of "Femme Fatale." Confident and self sufficient, she rarely gets time away from her admirers.
Jordan is a six-year-old who came to Nyaru Menteng after being rescued from an illegal stage show, where he was trained to wrestle with other orangutans. Having been stolen from his mother while still a baby, he has little experience interacting with other orangutans and enters the island at the bottom of the social hierarchy. Jordan once attacked alpha male Hamlet with a bottle, but Hamlet seemed to be understanding and didn't punish him severely. Owing to a deviated septum, Jordan has a constantly running nose. In episode 4, he attempted to drink the engine oil out of a bottle he has found, which would have killed him had the Teknisi not spotted him in time.
Jupiter is a female who takes a liking to water. She discovers a new food source, fish.
Kacio is a six-year-old female who shows that Chen Chen has a soft side by playing with him on the platform in episode 3. She is also a friend of Yeyen and Nadi.
Kiki is a 15-year-old female. Kiki was kept as a pet in a cage under a house, and she could not walk or climb when she was rescued—she rolled everywhere. She was released to Palas Island and now has become a regular on Orangutan Island.
Komo, a Palas Island male, could possibly take Chen Chen's position in the hierarchy.
Mac is a Palas Island male who visited Orangutan Island with Hamlet in Season 1. Something of a bully, he has tried to challenge Hamlet for dominance; he also makes Hamlet jealous.
Mangis was rescued when she was a toddler. Her nickname is "Spoilt Princess" because she is always lazy.
Manisa is a Palas Island female with looks similar to those of Sayla and Nor. Despite her large size, she is really a quiet and sweet orangutan.
Marly was introduced to Tati when Tati first came to Orangutan Island.
Mego is a Palas Island male. He came to Orangutan Island in season 2.
Mentos is a Palas Island female, part of the Palas Island Girl Gang, who is known for beating up Mangis and acting tough. She likes to assert her dominance whenever she can.
Mogok is a brave young male who challenges the much larger invader Chakra by stealing back the group's bananas. Earlier on in the season Mogok went missing, prompting Lone and the Teknisi to form a search party. Mogok is eventually found on the opposite side of the 100-acre (0.40 km2) island six days later, looking perfectly healthy. His six-day survival was a good sign for his fellow orangutans.
Mustafa is also one of the adults on Orangutan Island. He was released into Nyaru Menteng's new 10-acre (40,000 m2) forest.
Nadi was found in a small cage outside of a house suffering from severe malnourishment. Nadi hates boat rides after having been transported to Nyaru Menteng in a boat and has to be sedated during the boat trip to Palas 2. Hypervigilant, she is quick to sound the alarm at the first sign of potential danger. After a scuffle with Daisy, Nadi is bitten by a pit viper but recovers with the help of Nielsen.
Nor is a Palas Island female who wants to attack Mangis. She spies the Teknisi and the other Orangutan Island orangutans searching for Mangis.
Oren is Barata's best friend.
Oyoy was an independent male. After he went missing in episode 3, he was found dead, facedown in the river. Lone believes he fell out of a tree.
Papau at nine years of age is the oldest female on the island and is known for her maternal manner. She often cares for the shyer Bonita. Towards the end of season 1, she forms a bond with Hamlet.
Peanut is a two-year-old male orphan who appeared on episode 1 in season 2.
Pickle is Lone's roommate on episode 1 in season 2.
Randang is a female orangutan two to two and a half years old. When Bonita is sent to forest school to recover from an illness, Randang keeps climbing on Bonita's back as if she were his mother.
Reno is a six-year-old male who uses Hamlet's absence to challenge Chen Chen's dominance. He is strong, clever and a totally mean bully. He, along with Hamlet and Chen Chen, is one of the strongest on the island
Ruby is a three-year-old female whose mother was killed by poachers. She is saved and sent to the Nyaru Menteng Rescue Center. On the first episode in season 2, she is bitten by a macaque.
Sayla is a Palas Island female, part of the Palas Island Girl Gang. She usually has mud on her face.
Suka is introduced to Tati when Tati first arrives at Nyaru Menteng.
Tati is a two-year-old female who was kept in a cage by a hunter for three weeks. When she came to Nyaru Menteng Rescue Center, she was a bit aggressive at first but later on calmed down and joins the forest school. Her first friends were Suka and Marly.
Ujung is a 12-year-old male and Hamlet's old friend from Palas Island.
Yeyen is the mate of Chen Chen and is known for her ability to walk upright in water.
Zorro is a full-grown adult orangutan from Kaja Island who weighs almost 250 pounds.