NOTE: This is an official character from The Lion King: Six New Adventures books. This character is not seen in any of the movies.
When Ni was old enough to survive on his own, he left his pride. He wanders into the Pride Lands and saves Nala from a hyena. He is rather concerned with not being flaky, and Kula and Nala think that if he groomed his fur, he'd look cute. He is welcome to stay with the pride, but he insists that he wants his own pride, and leaves never to be seen again.
Ni appears in the book, Nala's Dare.