Koda is a young and playful cub and a free spirit. He is always up for adventure, which has led to various occurrences throughout his life. Because he has experienced much in his young life, Koda always has a story to tell (much to the initial chagrin of Kenai), and does not know when to shut his mouth. His stories often mention something questionable, as he was speaking at one point "...my eyes were watering, my tongue was swollen, and from that moment on, I was more careful about what I lick."
Though small and young, Koda is a lot more clever and smarter than he looks (knowing how to undo a hunter's trap to get Kenai down), but he seems to be lacking somewhat in common sense (as he tried to get Kenai down first by continuously whacking him with a stick, letting Kenai get it for himself, and not just undoing the trap to begin with). Despite this, it might have been intentional, as Koda wanted Kenai to escort him to the salmon run. Furthermore, Koda has apparently traveled far with his mother before he met Kenai, as he knows various landmarks throughout the Alaskan Wilderness, proving he is streetsmart. Koda's bond with Kenai was originally a working relationship, as the cub needed the older bear to escort him to the Salmon Run, whereas Kenai needed Koda to show him to where The Lights Touch the Earth. However, as they journey, they begin to bond and grow close over various adventures to the point where Kenai himself calls Koda a little brother. Sadly, this bond is broken when Kenai admits to Koda that he killed his mother. Heartbroken, Koda ran and refused to speak to Kenai, much less forgive him. Later, when he is alone, he witnesses an argument between the moose brothers Rutt and Tuke, which reminds Koda how much he and Kenai care for each other. He risks his life to save Kenai and was blown away when Kenai regained his humanity. In the end, their brotherhood proves true when Kenai forsakes his humanity, stating Koda needs him more than his people. Koda is overjoyed to have his brother back and witnesses his manhood ceremony.
By the next film, the two brothers have come out of hibernation and could not be closer. However, when they meet Kenai's old friend, Nita, Koda grows jealous, as the two old friends start ignoring him and he fears Kenai will go back with Nita. After an avalanche, Kenai and Koda make up. However, after Nita leaves, Koda can tell Kenai's heartbroken, so he puts Kenai's happiness before himself, asking his mother to remake Kenai a human, proving Koda cares more for Kenai's happiness than his own. Despite this, thanks to the spirits' guidance, Nita finds her heart belongs to Kenai and she and Koda have developed their own bond and, thus, she becomes a bear herself, marrying Kenai, giving Koda a newly adopted older sister-in-law figure.
Koda has a dark brown fur, a cream muzzle with a brown nose, brown eyes and brown ears, on his hands and feet, sharp brown claws, five fingers on each hand, and five toes on each foot. He also has brown pads on the bottom of his feet (in the hands, he has it too).
Koda is first seen rescuing Kenai (who was turned into a bear as punishment for killing one as revenge for killing Sitka) from a snare, and telling him that he and his mother were separated by several hunters (or "monsters" as Koda described them). At first, Kenai finds Koda annoying, but eventually, he becpmes attached to him. After one of the monsters (who turns out to be Kenai's remaining brother, Denahi, who thinks that Kenai was killed by a bear and wants to kill him, not realizing that the bear was Kenai the whole time), Koda helps Kenai escape by hiding in a glacier and later introducing himself. However, Kenai wants to become a human again, so as a result, he decides to accompany Kenai on his journey to the mountain "where the (Northern) lights touch the Earth." Along the way, they meet a pair of moose named Rutt and Tuke, who follow them on their journey, but then they decide to ride on several woolly mammoths to get to the mountain faster. After getting off their mammoths, but leaving the moose behind, Koda gets into an argument after Kenai becomes very annoyed with him, causing Koda to get angry with him and storm off. After helping Kenai escape Denahi again while in the lava fields, Koda, who now sees Kenai as his older brother, brings him to a waterfall at the base of the mountain where a salmon run is taking place there, and introduces Kenai to the troupe of bears who have gathered to catch some salmon. After Kenai and the other bears start getting used to each other and showing him that they are not the monsters Kenai thought, they become good friends until they decide to tell each other a story, and it is Koda's turn. Koda then tells the other bears the story of how the monsters separated him from his mother, resulting in him meeting Kenai until he gets to the part where "the monster had her backed up against this giant glacier!" Then, Kenai learns that the bear he had mercilessly hunted and killed had been Koda's mother. After Koda hears the truth, he runs away crying. However, after meeting the moose again and hearing their advice, Koda realizes that Kenai wants to protect him the whole time, and ascends the mountain, where he sees Kenai about to be killed by Denahi, and saves him by taking Denahi's spear, only for Denahi to try to kill him instead, prompting Kenai to save him, thus allowing Sitka to turn Kenai into a human again. After saying goodbye to his mother after seeing her as a ghost, it turns out that Koda no longer has a family, and as a result, Kenai chooses instead to stay a bear and live with Koda, who needs him more than any of his own people. Ironically, for this act of love, Kenai is declared to have become a man. In the credits of the movie, Koda is seen trying to teach the moose brothers martial arts.
In Brother Bear 2, Kenai and Koda awaken from hibernation to find that spring has arrived. Even with snow on the ground and the trees still bare, love is decidedly in the air. Kenai and Koda scoff at the notion of romance, but an old bear (Tug, who they were laughing at because a female bear that he likes was calling over for him to come to her) cautions them (Kenai in particular) that "You can't run from love. It has a way of tracking you down." Kenai laughs, but later has a dream about Nita, a girl he used to know when he was young and a human.
Meanwhile, in her own village, Nita is preparing for her wedding to a man named Atka. Surprisingly, when the big moment arrives, it is revealed that Nita cannot marry Atka. The reason for this is that when they were children, Kenai gave Nita an amulet as a gift. What neither Kenai nor Nita realized was that the amulet bound them as one. The only way for Nita to marry Atka now is to go with Kenai to Hokani Falls, where he first gave her the amulet, and burn it.
Nita finds Kenai and manages to convince him to help her. Initially, Koda gets along with her better than Kenai, relating a number of embarrassing stories about Kenai's early blunders; despite this, during the course of their three-day journey, their old friendship sprouts anew and flourishes- with the ultimate result that Koda feels left out. After Kenai and Nita burn the amulet (despite their feelings for each other) and Nita returns to her village, Koda decides that Kenai's happiness is more important to him than having a brother. To that end, he asks his mom to tell the spirits to turn Kenai back into a man so he can be with Nita. Then he goes into the village to inform Nita of this and is subsequently attacked by the villagers, prompting Kenai to come rescue him.
When the spirits show up, Koda explains that he asked them to change Kenai back. Kenai decides, however, that he cannot do that. Surprisingly, Nita decides that as long as the spirits are there, they can turn her into a bear. This they do, and shortly thereafter Kenai and Nita are married and Atka gets banished by the village. This, in return, gives Koda a new mother figure.
Koda is a meetable character in the Disney theme parks. Sometimes, he can be found for meet and greets in Storytellers' Cafe during breakfast time.
- Koda's personality, cub-like nature and ability to highly annoy Kenai while still maintaining both of their affections for each other is a lot like Ujurak in The Quest Begins from Erin Hunter's novel series Seekers.
- Originally, Koda was going to be an adult bear named Grizz who would serve as an older brother figure to Kenai, who teaches him the concept of brotherhood, and was going to be voiced by the late Michael Clark Duncan, who ironically voiced Tug in the final film. However, this did not work out so well, and as a result, the character was changed into a young bear cub like what viewers see in the film. Another reason why his age was lowered in the first place was so that the writers would find it better to make Kenai the more responsible older bear brother instead of the bratty younger bear brother.
- In the original film, he is four years old, and in the sequel, he is eight.