- "Oh, what is it? What is it?"
(A dog is heard barking)
"Wow! A puppy!"
- —Andy receives a puppy as his Christmas present
In Toy Story, Andy receives Buster as a puppy for his Christmas present at the film's resolution. Buster isn't seen, but he can be heard barking, and Andy says, "Wow, a puppy!" Both Woody and Buzz exchange worried smiles when they hear Andy say this because of their experience with Scud.
In the first issue of the Toy Story comic series, Buster is an excitable puppy who is aware that the toys can move and talk. He has a habit of chewing the toys as well as shaking and throwing them around. The Andy's toys try barricading him alphabet blocks and distracting him with stinky smelling dog biscuits, both of which don't work. The toys then try to make noise to stop him, but as Woody predicted that doesn't work either. When Buster accidentally gets Woody's pull string tugged on a ring stack, Woody's digitized voice gets his attention. The puppy then takes Woody's cowboy hat in his mouth and goes off.
Woody decides to train the puppy. He starts by barking orders in the style of the Green Army Men, but Buster's more interested in playing. Woody finds a stick and plays a game of throwing the stick for Buster to fetch and bring back. He gets friendly with the puppy, patting him on the head and stroking his tummy. Later Buster brings Woody his hat back. With puppy trained and befriended, he is no longer scary to the toys.
Toy Story 2
- (Buster's barking noise is heard from outside Andy's room)
Rex: "Oh! It's Buster!"
- Sarge: "Canine alert! Man your battle stations! Let's move, move, move!"
- ―The toys hear Buster barking as he runs up to Andy's room[src]
He is first shown as he bursts into Andy's room to find Woody, and after he takes Woody out of Andy's backpack, he pins Woody to the ground and growls at him, but quickly begins to lick him repeatedly after sensing that Woody is actually alive. It turns out that Buster and Woody were playing hide-and-seek. It's also implied that Buster had somehow been involved in the earlier disappearance of Woody's hat, as when Slinky Dog revealed he found Woody's hat as the good news, when Woody asked where he found it, Slinky admitted "well, that's the bad news...", with Buster starting to bark just after he said this.
Woody then asks Hamm how Buster did, and it is revealed that Buster set a new record of 13.5 seconds, as shown on Mr. Spell. A little later, when Andy's mother takes Wheezy with a broken squeaker, out to be sold at a yard sale, Woody, thinking quickly, whistles for Buster (though Woody had to use his other arm due to his good arm having been inadvertently broken by Andy earlier), and he takes him out to the yard sale (though Buster, when told to be "subtle," does it in an exaggerated manner before Woody pointed out he didn't mean that level of subtlety), where Woody climbs into a box to dig out Wheezy and bring him back to Andy's room. Unfortunately for Woody, Buster jumps over a toy while heading back to Andy's room, causing Woody to fall – which leads to the events of the movie.
At the end of the film, Buster is shown alongside Slinky, who understands that Buster wants to get out of the room, and Jessie performs a stunt with a Hot Wheels car and track to reach the doorknob to let Buster out. He is last seen when Woody sees Andy, Molly and their mother go out for another family outing.
Toy Story 3
- Molly: "Hey, aren’t you gonna say goodbye to Buster?"
- Andy: "Of course I will." (turns to Buster) "Who’s a good doggie? Who’s a good doggie? I’m gonna miss you."
- ―Andy says goodbye to Buster[src]
In Toy Story 3, Buster, now 10 years older, makes his final appearance. He is now very old, mixed brown and a little gray, has a gray-white snout, is fat, and is unable to help Woody and his friends, even though he continues to remain friends with them.
After seeing his friends getting thrown away by Andy's slightly aged mom, Woody, thinking quickly, whistles for Buster for help getting downstairs to rescue his friends from getting thrown away. However, after Woody hops onto Buster's back so he can run outside to save his friends, the elderly dachshund instead yawns and falls fast asleep on Woody. Then, Woody turns Buster around for air.
Buster is last seen being with a 17-year-old Andy when he departs for college, telling his pet dog to keep Molly away from his stuff.
Because he was still somewhat young in Toy Story 2, Buster was energetic, smart, and playful around Andy's toys, but whenever Andy was present, Buster acted like a confused dog. Buster is considered to be nice to the toys in Andy's room and is fiercely loyal to Woody.
In Toy Story 3, Buster is now an elderly, obese wiener dog who is a teensy bit weak to help Woody and his friends out, even though he remains nice and friendly to them.
- An early version of Buster, named "Speck" by the toys, appeared in the Toy Story comic story Pup and Circumstance, printed in the November 1996 issue of Disney Adventures. The character's name in the story was oddly not corrected when it was reprinted in the September 2005 issue.
- In Toy Story 2, Buster's ears are longer than his older self in Toy Story 3. The reason for this was probably to make Buster look more close to an appearance of a real wiener dog and can be considered a goof.
- Real-life dachshunds are believed to have a lifespan of around 12 years, so Buster would be considered quite old, 10 years old by Toy Story 3.
- He is one of the few pets, along with Hal and Dug.
- Buster is one of the few non-toy Toy Story characters who know toys can come to life.
- Buster is mentioned in one of the Toy Story That Time Forgot deleted scenes.
- Buster is named after one of Gary Rydstrom's dogs. In fact, he was named after the dog who provided Scud's barking noises.