Mufasa: The Lion King

Some time after Simba defeated his usurping uncle Scar and became King of the Pride Lands, he and Nala have a daughter, Kiara, and are expecting another cub. They leave for an oasis for the birth, leaving Timon and Pumbaa to watch over Kiara. Rafiki visits them and recounts the story of Kiara's grandfather Mufasa, with Timon and Pumbaa adding color commentary.
Years before, as a cub, Mufasa lives with his parents, Masego and Afia, in a coastal desert while dreaming of the legendary Milele, a lush oasis. A flash flood rages, seemingly killing the couple, and sweeps Mufasa into a wetland where he meets Taka, a royal cub. After surviving an attack by young crocodiles, Mufasa is accepted by Taka's mother Queen Eshe but tested by King Obasi, who races Taka and Mufasa to a dried tree to decide his fate. Taka deliberately loses so Mufasa can stay.
As time passes, the two brothers grow close, although Obasi prejudices outsiders. During a hunt on herd of oryxes, Mufasa kills one of two attacking white lions; the survivor warns Kiros, leader of the outcast Outsiders, who seek revenge for the death of the king’s son, Shaju. At Eshe and Obasi's urging, Taka and Mufasa flee so the former can continue Obasi's bloodline in a new kingdom elsewhere. King Kiros, along with his sisters Akua and Amara, leads an assault on Obasi's pride; massacring Obasi, Eshe, and their lions.
After escaping the pursuing Outsiders, the pair meet Sarabi, her hornbill scout Zazu, and a young Rafiki. Rafiki, guided by visions of reuniting with a brother, leads them toward Milele. Knowing that Mufasa is still alive, the Outsiders catch up to the group, forcing Sarabi to throw a beehive and cause an elephant stampede so they can escape. Taka falls for Sarabi but grows jealous when Mufasa saves her during the stampede. Out of loyalty, Mufasa credits Taka with Sarabi's rescue. As they travel through snowy mountains, Sarabi admits she knows Mufasa saved her, and the two fall in love. Feeling betrayed, Taka allies with Kiros, secretly leaving a trail for the Outsiders to follow his group.
At Milele, Rafiki identifies Mufasa as his "brother" from the vision. The Outsiders arrive to attack, and Mufasa discovers Taka's betrayal while battling Kiros in a full most swing. Trapped in a cave, Mufasa is nearly killed by Kiros until, upon realizing what he has done, a remorseful Taka intervenes. Kiros slashes across Taka's eye, leaving a scar. As the animals of Milele are rallied to battle the Outsiders by Mufasa, an earthquake strikes that kills most of the Outsiders, while Kiros drags Mufasa into an underwater cavern. A rockfall allows Mufasa (remembering Eshe's earlier advice) to defeat Kiros, and Taka saves Mufasa from drowning, fighting off the urge to drown him. Sarabi retrieves Mufasa from the cave but is aghast at Taka's actions.
After defeating Kiros, Mufasa becomes King of Milele and reunites with a surviving Afia, learning Masego has died in the flood. Taka apologizes to Mufasa, and his brother forgives him and allows him to stay but vows to never speak Taka's name again for his betrayal, prompting Taka to adopt the name "Scar" so he will never forget what he's done. Mufasa ascends the newly created and named Pride Rock and roars over his kingdom.
In the present, Kiara roars into the sky as Mufasa's spirit watches. Kiara reunites with Simba and Nala and meets her newborn brother, offering to tell him their grandfather's story.