Oliver appears as a small ginger kitten. About half-way through the film, he acquires a blue collar with his name on a gold tag. He is very brave and caring.
In the movie, Oliver is the main character and star of the film. Oliver is first seen in a box in New York City with other kittens who need homes. The other kittens are bought quickly, but Oliver is left in the box alone. One rainy night, Oliver gets out of the box to find a dryer spot to sleep but then he comes across some dogs who begin to chase him, but he manages to escape by jumping over a big fence where he finds a dry place to sleep on the top of a truck's wheel. The next day when Oliver hears the truck starting up, he jumps off and goes off to explore New York City. He soon meets a little boy about 3 years old and begins to play with him, but the boy's mother pulls him away telling him that he can play with Oliver some other time. Then Oliver smells hot dogs which are being sold by a guy named Louie and he tries to go and get some, but Louie shooes Oliver away. Oliver tries to get some of the hot dogs again but this time Louie kicks him away with his foot. Then Oliver meets a dog named Dodger who offers Oliver help to get the hot dogs to which at first Oliver refuses until he hears the rhythm of the ground from a jack hammer he accepts Dodger's help and asks Dodger when are they gonna get the hot dogs to which Dodger replies Right now and he begins to chase Oliver which distracts Louie and Dodger manages to get the hot dogs while Oliver manages to jump on Louie and then escape by jumping out a window and nearly getting mustered thrown at him by Louie. Then Oliver catches up to Dodger and asks him when are they gonna eat but Dodger denies that Oliver will get any and runs off into the city. Oliver chases after Dodger as Dodger sings (Why Should I Worry?). Oliver secretly follows Dodger to his barge home where he climbs up onto the roof and listens as Dodger gives his dog friends Francis, Rita, Tito and Einstein the hot dogs and tells them the story about how he got the hot dogs. Dodger describes Oliver as a monster coming right at him with burning eyes but before he can finish the story Oliver falls from the roof and into the barge where the gang run frighteningly thinking he's the monster but when they find out that he's a cat they ask him how he found their home. Oliver explains that he was the one who helped Dodger get the hot dogs and the gang laugh about Dodger's story. Then Fagin the owner comes in and sees Oliver but before he can examine him Sykes' two dogs Roscoe and DeSoto come in and shoo him out to talk with their master Sykes. Then DeSoto notices Oliver but Oliver manages to scratch him on the nose to which the two dogs try to attack him but Dodger and the gang manage to stand in front of Oliver and protect him and shoo the 2 evil dogs away to which Roscoe says Dodger and the gang will pay for what they've done starting with Oliver. Fagin walks in all wet (after falling off the pier) and says he saw DeSoto's nose and wondering who did it and is proud that it was Oliver after Fagin reads a story to them Dodger turns off the lights, hops on his bed, and goes sleep Oliver who is 2 second napping on Fagin's lap looks at him, runs to his bed and snuggles beside him Dodger smiles and curls beside him Oliver does this to show that he likes Dodger.
Role in the series
Oliver reprises his role from the movie. However, it is later revealed that he is Danny and Sawyer's true-born son, having been abandoned during a Heartless attack years ago alongside the rest of his kitten siblings (who at least have been adoubted to good homes). Halfway through the picture, Viper and Hiss, who had adopted him at the moment, discover this revelation and decide to give him to Jenny for safekeeping until Danny and Sawyer can come back to pick him up.