He first appears during the song "Two Worlds" and the beginning of the film, where he is seen playing with his father by climbing up his back and sliding off. He then runs to his mother Kala and she rubs her nose with his and then tosses him into the air.
One night, as the three of them sleep, the baby gorilla notices a frog hopping by and wanders away from his parents, chasing the frog deep into the jungle, unaware that the leopard, Sabor, is out hunting. When Sabor spots the baby, she begins chasing him; the Baby Gorilla tries to race back to his parents, but Sabor corners him.
Kerchak and Kala hear their son's cries as he's being eaten alive and race to try to protect him, but Kerchak realizes they won't be able to save him, so they stop in their tracks. Kala cries sadly in Kerchak's arms at the loss of her only child.
Soon after, Kala hears another baby crying, leading her to a treehouse, where finds a human baby boy whose parents were also killed by Sabor. Though Sabor is still inside the treehouse and gives chase, Kala manages to escape Sabor and save the baby. When Kala brings the baby back to her family and asks Kerchak if she can keep it, Kerchak tells Kala that the baby won't replace the one they lost but that she may keep him.
Kala then names the baby boy Tarzan. Even though Tarzan and Kala's biological son never meet, in a sense, they are technically brothers. His death is avenged by Tarzan when Sabor is finally killed.