Barbie

Barbie is a toy based on the popular real-life Mattel toy. She appears in Toy Story 2 as a minor character and in Toy Story 3 as a supporting protagonist.

Toy Story 2
A bunch of Barbies were first seen in Toy Story 2 partying in an aisle at Al's Toy Barn. Rex, Hamm, Mr. Potato Head, and Slinky drive by this aisle, looking for Woody, when the Barbies catch their attention. After Hamm asks for directions to Al, Tour Guide Barbie navigates them around Al's Toy Barn

After Andy's toys track down Al's suitcase at the airport to save Woody, they have a fight with the Prospector, who wants to take the Roundup Gang to Japan. Once they stop him by using the flash from cameras from someone else's luggage, they put him in a Barbie backpack. A girl named Amy retrieves the bag and puts her Barbie in the backpack next to him. She's surprised by the new "big ugly man doll," who she plans to give a makeover. The Barbie next to Stinky Pete tells him he'll like Amy because she's an artist, as she shows Amy's modifications to the other side of her face. The Prospector is horrified, but later reveals he enjoys his makeovers.

The morning after Andy's toys return home, Wheezy sings in celebration and three of Molly's Barbies provide backing vocals.

During the bloopers, two identical Barbies were conversing with the Prospector when he was supposed to be filming a scene. He said he would get them a part in Toy Story 3. Although this does not happen, a different Barbie does appear in Toy Story 3.

Toy Story 3
One of Molly's Barbie dolls had lasted up until this point, but she was later donated to Sunnyside Daycare Center, along with Andy's toys (who had snuck into the box bound for Sunnyside) now that he was going to college. Although Barbie was initially saddened, she soon caught sight of and fell in love with the Daycare's Ken (unaware that he worked under Lotso). However, discovering that Ken and the other Sunnyside toys had locked up her friends, Barbie broke up with Ken and was subsequently locked up with the rest of Andy's toys. She was part of Woody's plan to escape Sunnyside, when she distracted Ken by making him show her his many outfits and later tied up Ken and made him reveal where the manual to reset Buzz Lightyear was. She disguised herself using Ken's space suit and made Bookworm give her the Buzz Lightyear manual. She unscrewed Buzz's back compartment so Woody and Rex could have access to the "Play-Demo" switch and the reset hole, respectively. Despite Buzz still believing to be a real Space Ranger (but reset in Spanish), Barbie and the toys attempted to escape Sunnyside, but Lotso and his gang stop them. Ken then appears and his love for Barbie had made him stand up to his former master, effectively protecting her, as well as her friends. When the toys were being loaded in a garbage truck, Barbie wanted to help, but was stopped by Ken from risking her life.

She and Ken later made up, becoming Ken's girlfriend once again, and they both revolutionized Sunnyside, becoming its new leaders.

Trivia

 * Barbie was meant to appear in the original Toy Story as Woody's girlfriend, in place of Bo Peep. However, Mattel would not allow the use of Barbie because they didn't want her to be given her own personality (it was important to them that the girls who buy the toys would imagine what Barbie is like themselves, thus making the toy unique to each girl). After Toy Story was a success, Mattel decided to put that policy aside and allowed her to appear in Toy Story 2, and also with her boyfriend Ken in Toy Story 3.
 * In Toy Story 3, she is based on the real life 1983 Great Shape Barbie toy.