As an adolescent, Nuka was skinny and underfed. He had unkempt fur, scraggly whiskers, and a short ungroomed black mane. His main pelt was brown with a gray tint, while his muzzle, paws, and underbelly were cream. He had dark eye rims, a short black goatee, tufts of black fur on his elbows, and red eyes. Like most Outsiders, he had a hooked black nose and unsheathed claws. Once an adult, Nuka became larger and more muscular, though he remained thin and weakly built, especially compared to his brother, Kovu. His mane grew longer but remained scraggly and unkempt. Nuka was bombastic, highstrung, and volatile. Unlike his siblings, who were more long-suffering and scheming, he jumped into situations headfirst and displayed almost manic enthusiasm for Zira's plots. He was considerably neurotic and could lose his temper at a moment's notice, even if the issue was as trivial as itchy fur. His excitable nature sometimes got him into trouble, such as when he accidentally trapped himself in a ring of fire while setting the Pride Lands ablaze. Even so, he was a fierce fighter and took orders well. He was aggressive and persistent, and did not shy away from attacking much larger opponents like Simba. Despite being the eldest of Zira's cubs, Nuka was irresponsible and often neglected his duties. He liked to bully his younger siblings, either by making disparaging comments about them, laughing at them, or outright physically abusing them. Though he longed for Zira's attention, he did not share her enthusiasm for Kovu's position as the Chosen One and only reluctantly went along with her plans to put Kovu on the throne of Pride Rock. Because of Zira's favoritism, Nuka resented Kovu and wished he had been the Chosen One instead. He constantly vied for his mother's attention and deliberately tried to make Kovu look incompetent and unfavorable. Despite Nuka's best efforts, Zira continually ignored him, which only frustrated him further and made him try all the harder to capture her attention.