Glenn Close and Lance Henriksen reprise their roles as Kala and Kerchak from the first film while Harrison Chad, Brenda Grate, and Harrison Fahn are the new voices for the younger versions of Tarzan, Terk, and Tantor, replacing Alex D. Linz, Rosie O'Donnell, and Taylor Dempsey.

They are joined by new characters voiced by George Carlin, Estelle Harris, Brad Garrett, and Ron Perlman.

[3] As a young human orphan being raised by a family of gorillas in an African jungle, Tarzan is worried that a fabled monster known as the "Zugor" will someday catch him.

Alone in the jungle, Tarzan gets chased by Sabor the leopard into Dark Mountain, a rocky place inhabited by two hulking, spoiled gorilla brothers, Kago and Uto, and their controlling, over-protective mother Mama Gunda.

He uses hollow trees and the Dark Mountain's caves and tunnels as megaphones to amplify his voice and pretend to be a monster, scaring other jungle creatures away from his territory and food.

Terk and Tantor encounter trouble in Dark Mountain in the form of Mama Gunda, Uto, and Kago, but they are able to escape.

Mama Gunda, Uto, and Kago overhear their conversation and learn it was Zugor who was pretending to be the monster; he gets himself into trouble.

Kala and the baby gorillas arrive near Dark Mountain and also encounter trouble with Mama Gunda, Uto and Kago.