Susan Johnson is one of the two main protagonists of Disney's 1989 live-action film Cheetah, alongside Ted. She befriends a goat herder named Morogo and adopts an orphaned cheetah cub that call Duma. She is the daughter of Earl and Jean and the older sister of Ted.
She was portrayed by Lucy Deakins, who also played Cammie from The Great Outdoors.
Susan and her brother, Ted arrive at Kenya with their scientist parents for a six-month vacation. The next morning, they come notice a Masai tribe across the lake and Ted heads over. Susan tells him not to, but he ignores her and she follows. They take pictures and they meet a tribal boy named Morogo, who shows him the neighborhood and the local wildlife. They become best friends and they show each other their own skills. Eventually, their mother, Jean returns home and she is not happy. Susan convinces their parents that Morogo will help protect them from danger and they reluctantly aggree. One day, while they're playing soccer, their ball lands near a sleeping rhino. Morogo heads over and retrieves it as he places a stone onto the rhino's side. Morogo offers Ted to do the same and he heads over, despite Susan's warnings. However, the rhino wakes up and Ted flees.
Later, they come across an abandoned cheetah cub and head over there, despite Morogo's warnings that the mother will return. However, Morogo learns that the mother was killed by a poacher and Susan decides to adopt the cub, as it's the only way for her to survive. Susan and Ted convince the parents to adopt the cub, to which they reluctantly agree and they name her Duma.
6 months have passed and their vacation is almost over, which means that they have to release Duma into the wild. A game warden named Larry informs them that cheetahs lose their wild instinct when they're tamed. Mr. Patel offers to buy Duma, but Susan refuses and they leave his store. They train Duma to hunt with the help of Morogo and they come across a herd of gazelles. They release Duma to hunt them, but she refuses.
Before their vacation is over, Duma has been abducted by Patel and a pair of poachers. The next morning, the two kids wish Morogo goodbye and Ted convinces their parents about Duma's unexpected disappearance, but they ignore him. They head to Patel's store to get gasoline and Patel sees the tears in Susan's eyes as he asks about losing her pet. Ted realizes that Patel couldn't possibly know about Duma's disappearance and notices that the pattern on Abdullah's shoes resembles the marks during Duma's discovery, making him realize Patel's plan. They head back to the airport and the parents wish them goodbye. Ted informs Susan about the incident and despite now knowing this, she decides not to help. However, they delay their flight and send a telegram to their grandmother. They head back to Patel's store and discover him to be gone, but learn his whereabouts from his cousin. They head to Morogo's village and convince him to help them save Duma, but he refuses, fearing his parent's disapproval. But he gives them instructions to get to Jamhuri and they head out to find Duma across the Great Rift.
The next morning, Susan decides to head back and give up until Morogo comes to join them on their quest. Throughout the journey, they avoid dangerous obstacles and cross a lake full of hippos. They rest the following night and Morogo feeds them termites. The next morning, they dodge an elephant attack and finally arrive at their destination. Ted and Susan sneak into the camp the following night and discover a stack of fliers advertising Duma's race against greyhounds. They realize Patel's plan to make money and they manage to find Duma. However, they are captured by Abdullah and locked in a cage. As they leave with Duma, Morogo comes out of hiding and frees them.
They head out after the poachers and are caught by a policeman after their parents learned about their disappearance. However, they trick the policeman and they escape onto a shepherd's truck. The shepherd drops them off at Nairobi and they are chased by a merchant after Morogo accidentally breaks his spears, but they escape. They manage to arrive at Nairobi Downs just as Duma's race starts. As Duma loses her burst of speed, Ted grabs his whistle from a security guard and blows, allowing Duma to regain her steam and win. The kids are reunited with their parents and they head out to save Duma. They manage to rescue Duma from Abdullah and their parents scold them for leaving them as the poacher is arrested.
They arrive at Cheetah Valley and the parents ask why they should release Duma before their vacation is over, to which Ted explains that Duma is ready to hunt and they should release her right now. The kids notice another cheetah and they release Duma, but the stubborn cheetah refuses to leave their side. Susan orders Duma to go and she reluctantly does so. Duma heads over and plays with her new friend as the kids happily watch her run free.
She is based on Ngatua from Alan Caillou's original classic The Cheetahs.