Denahi is the older brother of Kenai and the younger brother of Sitka, thus making him a middle child. At some point, upon reaching manhood, he received a totem from his village's shaman woman Tanana know as the Wolf of Wisdom.
Denahi is first seen as an elderly man telling his story to the younger generations.
As a young man, he was seen fishing with Sitka, only for it to be cut short after Kenai unintentionally leads a large herd of caribou towards them. Fortunately, the brothers are able to avoid being trampled by the caribou, though Denahi is kicked in the back of the head by one of the caribou. Annoyed at Kenai, Denahi pins him to the ground and tries to drool on him, before being pulled off by Sitka. Kenai tells Sitka after today, Denahi cannot treat him like that anymore. Denahi realises that Kenai is referring to his manhood ceremony where he will receive a totem and replies that it does not matter what the spirits say as Kenai will always be his and Sitka's baby brother. Denahi and his brothers return to their tribe with Denahi instructing Kenai to tie up the basket with the fish they caught up high to avoid bears getting them. However as Kenai leaves to attend his ceremony, the rope suspending the basket comes loose, causing the basket to fall to the ground, spilling the fish.
Denahi later witnesses Kenai's totem-receiving and teases him for the totem being the "Bear of Love", before being sent away by Sitka to deal with the fish. Moments later, Denahi confronts Kenai over not tying up the basket properly (as it has been taken by a bear) and says that Kenai should have got the totem of pinheads. Sitka tries to calm the situation by saying that they'll just make another basket, but Denahi replies that it took him 2 weeks to make the basket and tells Sitka to get Kenai to do. Kenai leaves to get the basket back from the bear. Denahi and Sitka went after him and saw him getting attacked by the bear. As Kenai tries to save Denahi from falling down the side of a glacier, Sitka breaks the part of the glacier he is on with his spear and falls into the waters with the bear to save his brothers. Shortly thereafter, Kenai and Denahi hurry down to find Sitka, only to find his hood.
After Sitka's funeral, Kenai tries to convince Denahi that they should go after the bear. Denahi tells Kenai that even though he knows what he is feeling, killing the bear would be wrong; however, Kenai says that their brother is dead because of the "monster". Denahi says that he doesn't blame the bear for Sitka's death, implying that he instead blames Kenai. Denahi advises Kenai against avenging Sitka's death as it may anger the spirits, but a frustrated Kenai sets out to kill the bear anyway. Kenai does so and is transformed into a bear by Sitka as punishment. As Denahi arrives at the scene of the battle, he sees scraps of his brother's clothes and Kenai in his bear form. Thinking his brother lost the fight and was also killed by the bear, a saddened Denahi vows to avenge Kenai. He begins to hunt Kenai's bear form relentlessly across the wilderness, not understanding that the bear is actually his brother.
He first sees Kenai in the woods, where he hides behind a tree. When Denahi comes out to attack, Kenai sees him and tries to talk to him, still unaware he was a bear and that Denahi therefore could not understand him, so Denahi tries to stab and kill Kenai.
Denahi later sees Kenai in his bear form in a lava field. There, Denahi tries to kill him, but Kenai hits him and runs for it, along with Koda. When he gets up, he gets his spear and tries to break the log bridge that Kenai and Koda are trying to get across. He breaks the bridge, but luckily, Kenai and Koda manage to get to the other side and Denahi briefly gives up. Then he growls and tries to jump to the other side, but lands on the bridge instead. The log then falls, with Denahi, into the waters below, even though Kenai tried to save him.
Later, Denahi was seen trying to warm himself with a small campfire and was about to give up on avenging Kenai when he saw an eagle, recognizing it as Sitka, and followed it. Denahi reached the mountain where the (Northern) lights touched the earth and found Kenai in his bear form and attacked him again. Before he can kill Kenai, Koda jumps in and steals Denahi's spear. Denahi gives chase and Kenai chases after Denahi, telling him to leave Koda alone. During this, Sitka arrived and changed Kenai back into a human before Denahi suffered the same fate as Kenai. Shocked and confused, Denahi threw down his spear. When he sees how much Koda means to Kenai, he redeems himself, telling Kenai that he "looked a better as a bear" and that he will always be his little brother, no matter what Kenai chooses to be.
Later, Kenai was made known as a man, even in bear form, and Denahi was there to see and help his brother put a handprint on the wall, making his manhood official.
Denahi starts off as playful and likes to tease Kenai and is something of a bully to him, but still loves him in every way.
When Kenai goes to kill the bear to avenge Sitka, Denahi arrives, but only finds scraps of Kenai's clothes and Kenai as a bear. Misunderstanding this, Denahi thinks the bear has killed his brother. This makes him develop a more serious, bitter personality as he vows to avenge Kenai by killing the bear.
However, at the final battle of the film, his anger has descended to complete madness and evil (shown throughout the film as he slowly grows a mustache and goatee to give him a more sinister and mad appearance, giving a physical manifestation of his slow descent and corruption into madness in his pursuit for vengeance).
Denahi starts off as a mischievous, fun-loving character, but after Sitka dies, he becomes much more serious.
After Kenai transforms back into a human, Denahi is shocked to realize the bear he was hunting down was his brother the whole time and manages to reform, telling Kenai that he "looked better as a bear" and that no matter what he chooses to be, he will always be his brother.
Denahi shares the name with the peak of the same name, which also goes by the name Mount McKinley.
Denahi is the narrator of the film. Though the subtitles in the film mistake the narrator to be Sitka, it is shown at the beginning that he is the narrator when it shows an elderly Denahi, wearing his totem as he tells the story in Inuktitut, which is vocally translated to the audience.
Originally, Denahi was going to be Kenai's father instead of his older brother.
Even though Denahi was the main antagonist, Kenai ironically appeared to be the more malevolent character since killing Koda's mother was an offense to the Great Spirits and a posthumous Sitka then tried to stop Denahi from suffering the same fate as Kenai.
Denahi became a silent warrior after Kenai turned into a bear, aside from some angry growls, screams, and yells when the two fought. He did not start talking again until when he breaks the bridge in the lava field as he briefly yells out, "No!", then when he was warming himself with the campfire, and then again after Sitka changed Kenai back. This may have been due to the fact that, as pointed out by Tanana, bears cannot talk to humans and vice versa, so when Kenai begged Denahi to stop attacking him since he is his brother, all Denahi heard was him growling.
His totem is the Wolf of Wisdom.
Denahi did not appear in the sequel as his voice actor Jason Raize committed suicide in 2004, 2 years before the sequel was released.