When Sora, Donald, and Goofy meet Kerchak, his distrust of outsiders causes him to treat them rather coldly. He even ignores Tarzan's request to take them to the waterfalls. However, after Sora and company save the pack from Clayton, he lets them into the waterfalls, where Sora seals the Keyhole of Deep Jungle.
Kerchak is a large, adult male gorilla with black hair and grey skin. His forearms are enormous and his head is rather large. His eyes are brown and small in comparison to the rest of his head.
Kerchak is brave, powerful, and loyal. He cares a great deal about the gorilla family he leads, but his cold disposition gained after the death of his son causes those he loves to fear him. Kerchak also has a great hatred-like fear of outsiders of any kind, reacting aggressively when they are near. He is not without a heart, however, kind and almost loving to those he trusts, even outsiders that have gained that trust.
In Kingdom Hearts, Kerchak is leader of his gorilla family, taking great care of each member. He has a severe distrust of outsiders of any kind, as seen by how coldly he treats Sora and his friends. Once he learns he can trust Sora after Clayton's defeat, however, he grants the Keybearer and his friends access to the waterfalls, as Tarzan had previously requested.
Kerchak first appeared in Disney's 1999 animated film, Tarzan. Leader of a large family of gorillas, he is heartbroken when his only offspring is killed by the leopard Sabor. When his mate Kala brings the orphaned Tarzan into the family, he immediately orders her to take him back because of his fear of humans. He also tells her that Tarzan could never replace the child they had lost. Kerchak reluctantly allows Tarzan to remain amongst the gorillas in the end, but he doesn't consider the boy his son. His dislike for Tarzan only grows as the boy ages into a man, but the tension between the two dissipates when Tarzan kills Sabor and offers the leopard's body to Kerchak. Tarzan earns Kerchak's respect, but this is destroyed when Tarzan allows other humans (Jane, her father Professor Porter, and Clayton) to see the gorilla family against Kerchak's orders. Kerchak attacks the humans to protect his family, but Tarzan tackles the silverback and holds him down so that his new friends may escape unharmed. Tarzan decides to return to London with Jane after Kerchak accuses him of betraying his family, but he is captured by Clayton and his band of thugs. Clayton goes back to the jungle to hunt down the gorillas, and as his thugs round them up and put them in cages, he manages to capture Kerchak, claiming he'd be "better off stuffed". Tarzan returns along with Jane and Professor Porter to rescue his ape family, an action that touches Kerchak's heart. Kerchak defends Tarzan bravely, but he is shot by Clayton. After defeating Clayton, Tarzan approaches the wounded silverback, who makes amends with him and makes him his successor. Kerchak finally accepts Tarzan as his son, dying in his arms.