Miss Bianca is the female protagonist of Disney's 1977 animated feature film The Rescuers and its 1990 sequel. She works as the Hungarian ambassador for the Rescue Aid Society in New York City and is the partner, love interest, and eventual wife of Bernard.
Bianca is very concerned about her appearance as she can be seen putting on perfume and beauty powder. She's very beautiful, elegant, and graceful, which sets her apart from other Disney females. Despite her slight obsession with her appearance, she is very kind-hearted, compassionate, caring, and very unshallow. It is also shown that she is quite daring and has a love for adventure, as shown in certain scenes in the movies. She also has a strong sense of duty in her position in the Rescue Aid Society, placing her duty before anything else.
Miss Bianca arrives late at the Rescue Aid Society headquarters as they are singing their song. Before heading inside, she sprays herself with perfume and notices Bernard looking at her. Once she heads inside, she starts singing along, and the male members all turn and watch her with interested and respectful expressions. She sits down at her seat and the chairman calls forth the Mouse Scouts to bring a bottle containing a message into the gathering hall. Bernard is called forward with a comb that is to used as a ladder to retrieve the message inside the bottle. Bernard nearly hits the chairman, Bianca, and the other Society members as he struggles to keep it balanced over his head. After Bernard pulls the message out of the bottle, the chairman tries to read it but has trouble doing so. Bianca, however, is able to read the message and determine that it was written by a girl named "Penny." Showing concern for Penny, Bianca begs for the chairman to let her have the assignment. The chairman is hesitant at first but decides to let her go as long as she has a co-agent. Many of the male Society members volunteer, but ultimately, Bianca chooses Bernard, as she is attracted to him and believes that the two of them will be a great team.
Bianca and Bernard begin their search for clues at Morningside Orphanage where Penny once lived. Inside the orphanage, they meet a cat named Rufus. Rufus explains that the last time he saw Penny was after she did not get adopted by a couple visiting the orphanage. He goes on to say that Penny had been offered a ride by a sinister woman named Madame Medusa, the owner of a trashy pawn shop near the orphanage. Rufus believes that Medusa is most likely responsible for Penny's sudden disappearance.
Next, the team goes to Medusa's Pawn Shop. The shop is empty when they first enter, but soon Bianca finds one of Penny's school books. Bernard reasons that Penny must still be hidden somewhere in the shop. However, before they can investigate further, the telephone rings. The mice quickly hide as Madame Medusa enters and answers the phone. The mice overhear a conversation between Medusa and her accomplice Mr. Snoops. Medusa immediately asks whether Mr. Snoops had found "the diamond". When Snoops reveals that he had not and that Penny had been sending messages in bottles, Medusa is angered and decides to fly to Devil's Bayou that very night. Bernard stows away in Medusa's suitcase as she carelessly packs. Bianca tries to get in the suitcase but cannot and ends up riding on the floor of Medusa's car as it speeds down the street. The car (a convertible) makes a sharp turn and the suitcase falls out, taking Bianca and Bernard with it.
Although Bernard protests due to the abundance of the unlucky number 13 on the flight, Bianca flies with him on Orville the albatross to Devil's Bayou. She also begins to show that she is attracted to Bernard, kissing him on the nose to calm his worries and snuggling up to him on the flight. When in the process of landing, Penny escapes from the clutches of Madame Medusa, so she releases her two pet crocodiles, Brutus and Nero, to find her as well as going out in her swamp mobile. She orders Mr. Snoops to set off fireworks to illuminate the swamp for her. Orville is hit by one of them and crashes, although the two mice are unhurt thanks to Miss Bianca's umbrella. They meet up with two friendly bayou mice who would like nothing more than to rid the swamp of Madame Medusa and witness Penny being recaptured by Brutus and Nero. The bayou mice lend them their dragonfly Evinrude to use as a motorboat.
When they arrive at Madame Medusa's riverboat hideout, they hide from Medusa and her henchmen, but as Brutus and Nero pass them, Brutus smells Miss Bianca's perfume. He and Nero chase Miss Bianca and Bernard through the ship and ultimately into a large organ. While in there, Brutus/Nero, whichever one plays it while the other waits in ambush, starts playing the organ, which causes Bernard and Bianca to float up out of it in their attempt to eat them. Finally, Bernard flies out of the organ, and Brutus/Nero catches him in his mouth, to Bianca's horror. Medusa then tells her pet crocs to stop with the noise and hits Brutus/Nero with her cane causing him to spit Bernard out. Medusa then freaks out and attempt to kill him and Bianca along with Snoops by shooting them. When Medusa's shotgun jams, Bianca and Bernard take the opportunity to run, only to be shot at the last minute by one of Medusa's buckshot rounds when the gun is able to fire again. Luckily, the two survive and end up in the bayou and are found by Evinrude.
After being rescued, Bianca furiously wishes she was big enough to take on Medusa by saying quote, "Oooooh, if I was only a ten-foot mouse, I'd show her." Bernard then doubts that he and Bianca can rescue Penny because they are merely two little mice, but she reminds him that the Rescue Aid Society depends on them and can't quit after hearing the theme song in her head.
Bianca and Bernard see Penny out on the balcony of the ship. When she goes inside her room, the two mice observe her outside of a window as she prays. As Penny starts crying, the two mice are now inside and meet Penny, and Bianca consoles Penny because they have come to help her. Penny seems excited because her message (that was sent earlier at the beginning of the movie) had reached someone, but then she asks why she and Bernard didn't bring someone bigger with them (such as the police). Bianca then declares that the three of them should work together and have a little faith.
Together, Penny, Bernard, and Bianca concoct a plan to escape the bayou that night by first trapping Brutus and Nero in an elevator, followed by escaping in Medusa's swamp mobile and keeping her preoccupied with shooting off Mr. Snoops' fireworks in her room.
With the plan in motion, Bianca tells Penny to get dressed so they can put the plan into action. Bernard tells Evinrude to get Ellie Mae and the other swamp critters, but the plan is put on hold when Evinrude is cut off by a swarm of bats before he reaches Ellie Mae and Luke's cabin.
In the Black Hole, Bianca, Bernard, and Penny set off to find the Devil's Eye. Bianca is dreaded by the appearance of the cave. Penny informs her that it was once a pirate's cave. When Bianca asks Penny how she knows this, she answers by showing her the skeletal body of what was once a pirate with a sword stabbed in its chest.
After rescuing Bernard from falling into a dark hole in the cave, where the tide comes in, Bianca and Bernard continue searching for the Devil's Eye. When Penny holds her lantern up to a skeleton's head, they discover the Devil's Eye inside of it. The two mice try to get the diamond through the skull's left eye, but the diamond is too big. Luckily, with the help of Penny and a pirate sword, they are able to get the diamond out of the skull through the mouth and just barely escape the cave after the tide comes in and nearly drowns her, Bernard, and Penny in a whirlpool.
Later, Medusa is about to escape Devil's Bayou with Penny's teddy bear (which she has stuffed the diamond inside of), but Bianca and Bernard trip her with a rope while she's distracted, keeping her eyes on Snoops and Penny as she backs out of the room she's keeping them held in at gunpoint with her shotgun.
After Penny manages to get her teddy bear back and commandeer Medusa's Swampmobile, Bianca attempts to help her start the vehicle. With help from Bernard and the swamp critters, they manage to start the Swampmobile, but Medusa chases after them by holding onto a rope attached to the back of the Swampmobile and later using Brutus and Nero as water skis, whipping them with the rope, angering them. Bianca soon sees they are about to crash into the sinking riverboat, but Penny swerves just in time, causing the rope to snap and send Medusa crashing into one of the smokestacks, leaving her at the mercy of Brutus and Nero as Bianca, Bernard, Penny, and the swamp critters escape on the Swampmobile.
Back at the United Nations Headquarters in New York City, Bianca and Bernard learn on the news that the Devil's Eye has been donated to the Smithsonian Institute in Washington, D.C., while Penny has been adopted by a new mom and dad, thanking Bianca and Bernard, much to the reporter's confusion, but to the amusement of the Rescue Aid Society delegates. Evinrude then arrives with another call for help. Bianca volunteers herself and Bernard for the mission, taking off on Orville once more with Evinrude joining them, despite it being Friday the 13th and a nasty blizzard blowing through NYC at the time.
At the start of the sequel, Bianca and Bernard are at a fancy mouse restaurant, and though Bianca is enjoying the evening, Bernard seems very anxious, as he plans to propose to Bianca over dinner. Unfortunately, the ring slips out of a hole in his pocket and rolls away into the restaurant. After Bernard discreetly wanders off to retrieve the ring, Bianca is delivered a message from the Rescue Aid Society by the head waiter, François, requesting her and Bernard for a mission to Australia to rescue a young boy named Cody who had been kidnapped by the wanted poacher McLeach. When Bernard returns, Bianca informs him that François has told her about the mission, but he is completely focused on his proposal and believes that Bianca is talking about accepting. Upon returning to R.A.S. Headquarters, he discovers that he will be going with her on a mission to Australia.
Heading to Albatross Airlines to seek out Orville for a flight to Australia, they find that Orville has left the business in the hands of his younger brother Wilbur, who takes some convincing to agree to take Bianca and Bernard to Australia, especially throughout the blizzard raging through NYC at the time. They are soon forced to hitch a ride on a jumbo jet to make it all the way to Australia. Flying past the Sydney Opera House and the city proper, they then head for the Australian outback and the community of Mugwomp Flats to meet up with the R.A.S. regional operative there, a kangaroo mouse named Jake.
When they arrive at the airport where Jake works, Jake is at first annoyed by Wilbur trying to land despite warning him the runway is too short, calling him a "Crazy Yank", but is soon smitten upon seeing Miss Bianca and is more than happy to help them rescue Cody. While Wilbur is taken to the hospital to have his spine fixed, Bianca and Bernard go with Jake to find McLeach's hideout. When they are alone, Bernard attempts to propose to Bianca again but is interrupted when Jake arrives to tame a snake named Twister. From there, Bernard's repeated attempts to propose to Bianca are ruined in some way by Jake as they continue on their mission to save Cody.
That night, Bianca rides on a firefly with Bernard and Jake on their travels to find McLeach's lair.
Upon reaching McLeach's lair, they take cover on the door as McLeach pushes Cody out and tells him that his friend, Marahute, has been killed by another poacher, leaving her eggs without a mother to care for them. This is merely baiting to get Cody to lead McLeach right to Marahute's nest. Bianca, Bernard, and Jake hop aboard McLeach's truck and ride it to Marahute's nest. Once there, they climb down to warn Cody that McLeach tailed him, but when Marahute appears, returning to her nest, McLeach captures her, along with Cody, Bianca, and Jake. As McLeach then travels to Crocodile Falls to get rid of Cody, knowing that letting him go would mean trouble since Cody would report him to the Rangers, Bianca confides to Cody that Bernard would rescue them. Jake thinks she was instilling false hope in Cody, but Bianca tells Jake she was being honest, having full trust in Bernard, despite how it seemed like any chance of Bernard helping them was fading due to how much ground Bernard would have to make up to get from Marahute's nest to Crocodile Falls on foot compared to all them riding in McLeach's truck.
Taking them to Crocodile Falls, McLeach prepares to feed Cody to the crocodiles but finds his truck suddenly disabled by something swiping the keys, forcing him to use his scoped rifle to sever the rope holding Cody instead. It turns out that Bernard had caught up to them and swiped the keys, which he then gives to Bianca and Jake to free Marahute while Bernard dealt with McLeach and Joanna. They free Marahute just as Bernard's attempts to save Cody fail, and the two of them are about to go over the waterfall to join McLeach in death, but Marahute saves them just in time. As Bianca congratulates Bernard for his heroism, Bernard makes certain that his proposal is not interrupted and asks Bianca to become his wife. She happily accepts as Jake looks on with respect, and Cody has Marahute fly them home to his house.
Bianca made occasional cameos on House of Mouse.
Bianca, along with Bernard, made appearances at Walt Disney World and Disneyland in the years following the original film's release. They currently don't make appearances at the American parks, although she and Bernard continue to appear regularly at Tokyo Disney Resort.
- Miss Bianca's Hungarian nationality comes from her voice actress, Eva Gabor, who was born in Hungary; Gabor has also voiced Duchess in the AristoCats.
- It is also possible that Miss Bianca was born in Budapest, as Eva Gabor was born in Budapest.
- In Frank Angones' unproduced pitch for a Chip 'n Dale Rescue Rangers reboot, it is noted that Bianca's whereabours following the Rescue Aid Society's disbandment are unknown.
- "Bianca," which is the singular feminine form of "Bianco," is Italian for "white," appropriately describing her fur color.