|"You're not a true brown bear. If you were, you'd come with me and leave these others behind. No wonder Ujurak left you!"|
|— Nanulak to Toklo in Island of Shadows, page 280|
In the Return to the Wild arc
Island of Shadows
- Nanulak was found alone by Lusa, Toklo, Kallik, and Yakone on the Island of Shadows. He tells the other bears that his mother and half-siblings drove him out because they didn't have enough food, and the polar bears hated him for being a half-polar bear and half grizzly.
- He joins the group, and Toklo is happy to have a bear needing his protection once again. However, Ujurak appears in the bears' dreams, hinting that Nanulak isn't what he seems. Toklo refuses to listen to Ujurak and takes care of Nanulak, even after Lusa tells him Nanulak refused to help her when she had her paw stuck and Nanulak accidentally pushed Kallik, nearly resulting in her falling off a cliff.
- When they run into a family of grolar bears, Nanulak acts upset. Ujurak tells Toklo to go back to where they had found Nanulak, and finally, turning a deaf ear to Nanulak's protesting, the group heads there.
- There, Yakone spots a group of white bears, and to everyone's shock, Nanulak insists they head there. They go, and Nanulak points out a large male, saying he hurt him and asks Toklo to fight him. Toklo accuses the White Bear of fighting cubs and he denies.
- After they fight the bear gives in, but Nanulak rushes out of his hiding place, telling Toklo to kill him. The bear recognizes Nanulak and he is revealed to be Nanulak's father. The Seekers finally know the truth: Nanulak ran away, hating his parents because he was half and half. Before they can do anything, Nanulak's mother arrives with his half-siblings, though Nanulak growls and tells them that he hates them both. Toklo tells Nanulak that he will not abandon his friends to travel with him, as real friends tell the truth. Nanulak gets furious and leaves, running into the mountains.
The Melting Sea
- Nanulak is mentioned in Toklo's thoughts, and Toklo is glad that Nanulak wasn't with them.
- When Chenoa wants to travel with the Seekers, Toklo refuses, thinking that she was like Nanulak, only coming with them for protection. He hears Nanulak in his thoughts, accusing him of betraying him. However, he changes his mind when he realizes that she isn't like him.
The Longest Day
- Nanulak is revealed to be the one who ruined the fishing trials for the grizzly bears. Eventually, Nanulak attacks Toklo and they fight. During the fight, Toklo and Nanulak accidentally spill fire on the floor of a flat-face den. Nanulak runs off into the forest as the den catches on fire.
- He reappears as the bears reach safety in the river and attacks Toklo again. Toklo finally wins the fight by hitting Nanulak against a jagged rock. He tries to save Nanulak, but Aiyanna prevents him.
- Nanulak's name is also what grolar bears are also known as.
- His name is a mixture of "nanuk" which means polar bear in Inuktitut; and "aklak" which means grizzly bear in Inuktitut.
= Gender Unknown