Gustav wears a dark brown shirt with light brown sleeves held on with a leather belt. He has brown sandals on his feet.
Gustav constantly terrorized a kingdom, unopposed. In fact, he was just looking for some food and rest, but his innocent intentions were unknown by the townsfolk, once no one there ever wanted to talk to him. Then, Mickey Mouse, the tailor of the film's title, was ordered to slay him by the King (Minnie Mouse's father), who mistakenly thought he killed seven giants in one blow, Mickey gets shocked and desperate when he finds out that his task is to stop a giant, but he has no choice unless accepting it.
Later, Mickey goes to the woods and starts complaining his situation, in self-pitty. Then, Gustav appears and walks into the village, destroying everything in his way, without knowing that. Mickey and the other local villagers run away in fear. The hero hides in a wooden cart full of fresh pumpkins, but Gustav decides to sit in a house there to get some rest after his long walk. When Gustav sees the amount of pumpkins there, he doesn’t resist and grabs them with his hand to have a snack. Accidentally, he eats Mickey at the same time. The mouse manages to not being totally swallowed, but moments later, Gustav have a hiccup attack due to the pumpkins and decide to drink the water from a well to ease his hiccups, making Mickey fall across his throat to his stomach. Luckily, the mouse is rescued from there by the well rope when the giant throws the well away after drinking. After his luncheon, Gustav sees an amount of hay where Mickey is hidden and decides to use it to make himself a cigarette. When it’s done, he starts smoking, causing Mickey to sneeze. That’s when Gustav notices the presence of his enemy.
Initially, the giant doesn’t see the mouse as a threat and even finds it cute, but Mickey loses his patience with him and hits Gustav’s nose with his scissors, enraging Gustav, who tries to smash Mickey with his enormous hands. Quickly, the mouse escapes into the giant’s sleeve and fools him, making him get tangled in his threads. Unbalanced, the giant falls onto the ground and falls asleep due to his head hitting.
He was last seen sleeping, his snoring powering the merry-go-round, which Mickey and Minnie were riding. It is implied that Gustav woke up later and walked free, once he used to appear in some Disney comic books later. However, it’s very probable that he learned his lesson and stopped robbing. He even starts a new job, as a woodsman.
Originally unnamed in both the short and its comic adaptation in the Mickey Mouse newspaper comic strip, Gustav was given that name in the comic book story "Thumper Meets the Seven Dwarfs", originally printed as Four Color Comic #19. In the comic, when Doc is reading the story of "The Giant and the Tailor" to Thumper, he suddenly shows up outside the cottage and abducts Thumper. He takes him to his castle, where he and his wife decide to keep him for a pet. He places him in his pet canary Klaus' birdcage as a new playmate for him. Fortunately, Doc and Dopey suddenly show up to save him and help him escape.
Gustav later appeared in one of the Walt Disney Fun-to-Read Library books, Mickey Meets the Giant. He was attacking the village of Cedar Grove and Mickey has to use his wits to take him out like in the film. In the book, Mickey manages to defeat him by, in a test of strength, crushing a rock and have water come out of it (it was actually a meal sponge) causing the giant to flee in terror.
- Several of Gustav's actions were reused for Willie the Giant's movements.