Kitty Katswell and Kristina meet the Rescuers '(also called '"Kitsandra Katswell's Adventures of the Rescuers") is an upcoming full-length crossover film starring Kitty Katswell, and debuting co-stars, Kristina Kitten, Dudley Puppy and Madame Catastrophe. The film tells how Kitty Katswell and Dudley Puppy teamed up with Bernard and Miss Bianca to rescue a young girl named Penny and Kitty's twin sister, Madame Catastrophe, from Madame Medusa and Mr. Snoops and how the group thwarted a jewel heist at the same time.
The film begins in an abandoned river boat in Devil's Bayou, where orphan Penny and a chained-up Madame Catastrophe drop a message in a bottle containing a plea for help into the river. The bottle is carried out to sea and washes up in New York, where it is recovered by the Rescue Aid Society, formed by mice and their dog sponsor, Dudley Puppy. The Hungarian representative, Miss Bianca, volunteers to accept the case and chooses the janitor Bernard as her co-agent. The two visit Morningside Orphanage, where Penny lived, and meet an old cat named Rufus. He tells them about a wicked woman named Madame Medusa who once tried to lure Penny into her car and may have abducted Penny this time. At the same time, Kitsandra Katswell and her companion, Kristina had been listening in on the briefing, having beng on the search for Kitty's twin sister, Madame Catastrophe, who went missing the same day Penny did. They head off to Devil's Bayou ahead of the mice, not realizing Dudley has stowed away in the T.U.F.F. Mobile
The mice travel to Medusa's pawn shop, where they discover that she and her partner, Mr. Snoops, are on a quest to find the world's largest diamond, the Devil's Eye, and Mr. Snoops is in the Devil's Bayou with Penny and Madame Catastrophe, whom they have indeed kidnapped. With the help of an albatross named Orville, and a dragonfly named Evinrude, the mice follow Medusa to the bayou. Kitty and Kristina meet up with them there and tell them about their mission to find Kitty's sister and in return, they'd help the mice with their quest. There, they learn that Penny and Catastrophe were captured to enter a hole that leads down into the pirates' cave where the Devil's Eye is located.
Thanks to Miss Bianca's perfume, the group attracts the attention of Medusa's pet alligators, Brutus and Nero. Kitty, Dudley, Kristina, Bernard and Miss Bianca escape, and find Penny and Catastrophe. Wanting to escape tonight, Bernard orders Evinrude to get Ellie Mae and the other neighbours who loathe Medusa, which he accepts. However, in the middle of his quest, Evinrude is thwarted by a flock of hungry bats, delaying him. The following morning, Medusa and Mr Snoops send Penny and Catastrophe down into the cave to find the gem, unaware that Miss Bianca and Bernard are hiding in Penny's skirt pocket. Kristina, Kitty and Dudley wait outside for the group also. The four soon find the stone within a pirate skull; as Penny pries the mouth open with a sword, the mice push it out from within, but soon the oceanic tide rises and floods the cave. Miss Bianca, Penny, Catastrophe and Bernard barely manage to retrieve the diamond and escape.
The greedy Medusa steals the diamond for herself, attempting to run off with the diamond, leaving Snoops without any shares, and hides it in Penny's teddy bear. When she trips over a cable set as a trap by Dudley, Kristina, Bernard and Bianca, Medusa loses the bear to Penny, who runs away with it, followed by Kitty and Madame Catastrophe. Medusa retaliates with gunfire, causing Dudley and the mice to flee until they are met by Brutus and Nero, her alligators. With help from Ellie Mae and her neighbours, Dudley, Bernard and Miss Bianca trick them into entering a cage-like elevator, trapping them.
Two of the gang set off Mr. Snoops's fireworks, making the boat sink. Meanwhile Penny, Kristina, Catastrophe, Kitty, Dudley and the mice commandeer Medusa's "swampmobile," a motor-boat used by Medusa to travel in the swamp. Medusa attempts pursuit, but is thwarted. Medusa is left clinged to the boat's smoke stacks with Brutus and Nero attacking below.
Back in New York, the Rescue Aid Society watch TV to hear that the Devil's Eye is given to the Smithsonian Institution and Penny is adopted by a new father and mother. Dudley has been promoted to field agent and works with Madame Catastrophe, Kitty and Kristina. Bernard and Miss Bianca remain partners in the Rescue Aid Society's missions and soon after depart on Orville, accompanied by Evinrude, to a new rescue mission.
- Bob Newhart as Bernard, Rescue Aid Society's timid janitor, who reluctantly tags along with Miss Bianca on her journey to the Devil's Bayou to rescue Penny. He is highly superstitious and dislikes flying.
- Eva Gabor as Miss Bianca, the Hungarian female representative of the Rescue Aid Society. She is sophisticated and adventurous, and fond of Bernard, choosing him as her co-agent as she sets out to rescue Penny. Her Hungarian nationality was derived from that of her voice actress, Eva Gabor.
- Jerry Trainor as Dudley Puppy, the Rescue Aid Society's sponsoring dog who dreams to be a field agent. He stows away in the T.U.F.F. Mobile when Kitty flies ahead to Devil's Bayou to find her missing twin sister, Madame Catastrophe.
- Grey DeLisle as Kitty Katswell and Madame Catastrophe, a sibling team at T.U.F.F. who are also close allies with the R.A.S. Madame Catastrophe was originally sent to find Penny, but when she was close to finding her, Medusa and Snoops kidnapped her as well, planning to sell her to an exotic pet shop for a hefty sum of money. Kitty learns from her cousin Rufus, that Catastrophe is being held in Devil's Bayou with Penny and she flies off ahead to try and rescue her herself. She also helps Bernard and Bianca with their mission to rescue Penny.
- Geraldine Page as Madame Medusa, a greedy, redheaded, wicked pawnshop owner and the lead villainess/antagonist of the film. Upon discovering the Devil's Eye diamond hidden in a blowhole, she kidnaps the small orphan, Penny, to retrieve it for her, as Penny is the only one small enough to fit in it. In the end, she is thwarted and presumably eaten by her two alligators, Brutus and Nero.
- Michelle Stacy as Penny, a lonely orphan girl, residing at Morningside Orphanage in New York City. She is kidnapped by Medusa in an attempt to retrieve the world's largest diamond, the Devil's Eye.
- Joe Flynn as Mr. Snoops, Medusa's clumsy business partner, who obeys his boss's orders to share the Devil's Eye. Upon being betrayed by Medusa, however, he turns on her and flees by raft. This was Flynn's final role before his death in 1974.
- Jim Jordan as Orville, an albatross who gives Bernard and Bianca a ride to Devil's Bayou. The role was the last for Jordan, who retired after the film's release.
- John McIntire as Rufus, the elderly cat who resides at Morningside Orphanage and comforts Penny when she is sad. Although his time onscreen is rather brief, he provides the film's most important theme, faith. He was designed by animator Ollie Johnston, who retired after this film following a 40-year career with Disney.
- Jeanette Nolan as Ellie Mae and Pat Buttram as Luke, two muskrats who reside in a Southern-style home on a patch of land in Devil's Bayou. Luke is particularly known for drinking homemadeliquor, which really packs a punch.
- James MacDonald as Evinrude, a dragonfly who mans a leaf boat across Devil's Bayou, giving Bernard and Miss Bianca a ride across the swamp waters. His name is derived from the Evinrude Outboard Motors company.
- Candy Candido as Brutus and Nero, Medusa's two aggressive pet alligators, who return Penny after she attempts to run away. They are last seen attacking Medusa after she betrays them.
- Bernard Fox as Mr. Chairman, the chairman to the Rescue Aid Society.
- George Lindsey as Deadeye, a fisher rabbit who is one of Luke and Ellie Mae's friends.
- Larry Clemmons as Gramps, a grumpy old turtle who carries a brown cane.
- Dub Taylor as Digger, a mole
- John Fiedler as Deacon Owl
- Shelby Flint as Singer, Bottle
- Bill McMillian as T.V. Announcer
- This film marks the first appearance of Kristina Kitten, Dudley Puppy and Madame Catastrophe in one of Kitty's adventure films.
- Kristina and Kitty have a sisterly bond with each other, which is revealed in this film.