Doug's Fat Cat is the first part of the first episode of season three of Nickelodeon's Doug.
Roger goes to a monster truck show with his mother and asks Doug to take care of Stinky while they're away, but with disastrous results. Or is it?
While Doug and Judy are playing Barnyard Chess at home, Doug states voice-over that he never anticipated a cat to give him so much grief. Doug wins Barnyard Chess and beats Judy before Roger rings the doorbell.
Later, Doug answers the door to find Roger, who offers Doug to take care of his pet cat Stinky while he and his mother are attending a Monster Truck show in Doug's old hometown of Bloatsberg since the hotel he and his mother are staying at doesn't allow pets.
Doug's imagination: While Stinky is wreaking havoc at the Funnie house, Doug is calling to report the cat and arrest him. Stinky's chaos causes the whole house to fall apart, and Doug tells the caller to forget about it.
Doug reluctantly agrees to take care of Stinky and Roger offers him the materials he needs to take care of Stinky and right before he and his mother ride away, he tells Doug to feed Stinky a can of Skinny Kitty Diet Cat Food due to the cat acting sick. He also tells Doug that he is counting on him and rides away with his mother. As Doug is about to walk inside the house, Stinky ties his shoelaces together, causing him to fall and drop all the materials Roger gave him earlier.
Later that night, while Doug is reading a list of things he has to do to take care of Stinky, he sees that Stinky is missing. He then finds the cat outside howling with the other cats. Porkchop, trying to get some sleep, is annoyed of the cats' howling and sprays them with the water hose. Doug gets in the middle of the altercation and ends up getting soaked as well.
Later, Doug offers him the Skinny Kitty Diet Cat Food, but Stinky refuses to devour it and Doug unwilling asks him if he would eat pizza and ice cream instead, prompting the cat to ask for them. Doug refuses, demanding him that he is on a diet. Stinky howls his loudest, which wakes up nearly everyone on Jumbo Street. Doug does everything to persuade the cat to eat his cat food instead. He ends up eating it himself and runs into the bathroom to puke. In deference, he reluctantly gives Stinky pizza and ice cream.
The next day, when Doug (dressed in his pajamas in both episodes Doug's Garage Band and Doug's Christmas Story) wakes up, Stinky is missing. After an exhaustive search for the cat around the house, Doug finally finds him inside the trunk in Judy's room, where he discovers that Stinky has become fat and sick. Doug is worried that Roger will kill him if the latter found out about it.
Doug's imagination: Doug is calling Roger about the sick cat. Roger suddenly appears through the phone and strangles Doug right before pulling him inside. Doug is later seen strapped to a car, with a furious Roger about to run him over with a monster truck. Doug hopelessly lets out a scream.
Stinky is then seen lying on a basket inside Doug's closet howling in pain as Doug and Skeeter watch. Just then, the phone rings. Doug answers it and gets a call from him and Roger wants to talk to Stinky. Skeeter feigns a cat's meow, but Roger is quick to catch on to Skeeter's fake meow and demands him to put Stinky on the phone. Realizing that he has no other choice, Doug decides to tell him that Stinky is sick and he has to take him to the vet, much to Roger's rage and he hangs up.
Doug and Skeeter ride their bicycles to take Stinky to the vet as the cat continues to howl in pain. At the vet, Doug prances around the waiting room and decides to go into the doctor's room to ask questions. When he steps into the room, he overhears the veterinarians talking about the cat's fate and Doug soon becomes convinced that Stinky has passed away. Suddenly, a weeping Doug is comforted by Skeeter. (This theme is used as the same theme in the episode Doug's Christmas Story.)
When a worried Roger and his mother finally arrive at the vet, while Roger, who begins weeping, asks Doug where his cat is, Doug explains everything to Roger and to the two's surprise, the veterinarians bring Stinky to the waiting room. (This theme is used as the same theme in the two episodes Doug's Hot Property and Doug's Brainy Buddy.) Doug and Roger find out that Stinky is, in fact, a female cat and has given birth to kittens. Porkchop fainted at the sight of them.
One of the vets explains to Doug that feeding Stinky pizza and ice cream was the cause of the cat giving birth to the kittens. Doug tells Skeeter that he is glad that he told Roger about Stinky, considering that he would want Roger to tell him about Porkchop if he had taken care of him. Doug and Skeeter laugh as they watch Porkchop playing with one of the kittens.
- This episode is the Season 3 premiere.
- The drumroll at the end of the episode intro is no longer heard.
- This is the first episode in which Porkchop paints the apostrophe 'S' behind Doug's name rather than have it appear on its own when needed in the title introduction.
- It is revealed in this episode that Roger never knew his own cat's gender.
- Error - When Doug fills Stinky's cat bowl, the name is misspelled "Stiniky". When he places it on the floor, it's spelled correctly.