is one of the show's ten main characters, as well as one of the two main villains along with
. She was created by
. Stephen called his wife "the funniest person he knows"
and her sense of humor inspired the cartoon Karen's personality.
Role in episode
" Plankton!" (
tr) Debut (wall form); she analyzes a piece of seaweed and Plankton.
" F.U.N." (
tr) Supporting; she gives Plankton the plan to trick SpongeBob.
" Sleepy Time" (
tr) Cameo (desktop form); her rarely-seen desktop form is on Plankton's desk.
" Imitation Krabs" (
tr) Supporting (Robot Krabs form); her system is built into Robot Krabs, and her voice announces the self-destruct mode.
" Welcome to the Chum Bucket" (
tr) Supporting; she gives Plankton the plan to show SpongeBob some compassion.
" The Algae's Always Greener" (
tr) Supporting; she gives Plankton the plan to use his transmogrifier.
" Plankton's Army" (
tr) Major; she helps and consoles Plankton after his failures, and later meets Plankton's cousins. She learns Plankton's first name, Sheldon.
" Fear of a Krabby Patty" (
tr) Minor; Plankton asks Karen why she isn't laughing with him. Note: This is Karen and Plankton's first appearance as official main cast members, as they were both promoted in the credits of the 2004 movie.
" Krabs vs. Plankton" (
tr) Minor; she gives a depressed Plankton words of support.
" Dunces and Dragons" (
tr) Supporting, Karen's medieval ancestor appears as a crystal ball.
" Enemy In-Law" (
tr) Major; Plankton is bored and annoyed with her and wants to find a new romance.
" New Leaf" (
tr) Cameo, Robot Krabs form; the Robot Krabs (which has Karen's system built into it) appears.
" Best Frenemies" (
tr) Supporting; she analyzes the Kelp Shakes and finds out what they are made of.
" Friend or Foe" (
tr) Major; she tells the real story of how Plankton and Mr. Krabs became enemies.
" Spy Buddies" (
tr) Non-speaking cameo; Plankton talks to her from off-screen, and she is later seen in the Chum Bucket.
" Krabs à la Mode" (
tr) Supporting; Karen gives Plankton the idea to steal a Krabby Patty in the cold confusion.
" Bucket Sweet Bucket" (
tr) Major; she wants the Chum Bucke to have a makeover.
" Goo Goo Gas" (
tr) Major; she tells Plankton how to make his plan really work.
" Atlantis SquarePantis" (
tr) Appears in video game adaptation
" Mermaid Man vs. SpongeBob" (
tr) Supporting; she brings Plankton a Mermaid Man kids' meal.
" 20,000 Patties Under the Sea" (
tr) Karen's voice is built into the Chum Bucket glove and says "Customer approaching." Her control panel is also seen in the Chum Bucket.
" Banned in Bikini Bottom" (
tr) Supporting; she explains that the Krusty Krab was closed down.
" Krabby Road" (
tr) Supporting; she throws Plankton out of the Chum Bucket for being a jailbird.
" Spongicus" (
tr) Supporting; she is Plankton's helper at the Chum Coliseum.
" Patty Caper" (
tr) Minor; she gives Plankton their own version of a Krabby Patty.
" Plankton's Regular" (
tr) Major; she pays Nat to eat at the Chum Bucket.
" The Krabby Kronicle" (
tr) Minor; Plankton tries to show Karen a chum stick when the restaurant gets shut down. Later, Karen is seen powered off when Plankton is out of business.
" Komputer Overload" (
tr) Major; Plankton tries to replace Karen with an army of new robots.
" Chum Bucket Supreme" (
tr) Supporting; she gives Plankton the idea to advertise his products.
" Single Cell Anniversary" (
tr) Major; it is Karen and Plankton's anniversary, and Plankton gets SpongeBob to help him find a gift for Karen.
" Truth or Square" (
tr) Supporting; she gives Plankton the courage to go out and steal the formula. All three of her main forms are seen in this episode: wall, desktop, and mobile.
" Chum Caverns" (
tr) Major; Karen gives Plankton the directions to the cavern, and later gives him the plan to use the scenery to attract customers.
" Tentacle-Vision" (
tr) Cameo; Plankton watches the show on Karen's screen.
" Someone's in the Kitchen with Sandy" (
tr) Supporting; Karen thinks Plankton's plan is repulsive.
" The Inside Job" (
tr) Major; Karen gives Plankton her mind connector to get inside other people's brains.
" Greasy Buffoons" (
tr) Supporting; Karen helps serve the greasy food.
" SpongeBob's Last Stand" (
tr) Minor; Karen gives Plankton a back massage.
" One Coarse Meal" (
tr) Supporting; Karen doesn't believe that Pearl is actually following Plankton.
" Gramma's Secret Recipe" (
tr) Indirectly mentioned as "family"
" The Great Patty Caper" (
tr) Non-speaking cameo; Plankton says goodbye to her.
" Buried in Time" (
tr) Cameo; she watches Plankton in his restroom.
" Shellback Shenanigans" (
tr) Supporting; she uses her telescope to spy on SpongeBob and Mr. Krabs.
" Perfect Chemistry" (
tr) Supporting; Sandy compliments Karen when she visits.
" Frozen Face-Off" (
tr) Major; after Plankton leaves Karen in the snow, she teams up with SpongeBob to stop Plankton.
" Sweet and Sour Squid" (
tr) Minor; Plankton shows Karen his idea.
" Walking the Plankton" (
tr) Major; Karen and Plankton go on their second honeymoon.
" Plankton's Good Eye" (
tr) Major; Karen gives Plankton the eye surgery.
" Fiasco!" (
tr) Deleted scene, credited in voice cast
" Free Samples" (
tr) Supporting; Karen is confused by Plankton's free sample idea.
" Karen 2.0" (
tr) Major; Plankton builds a new version of Karen, making her feel devastated.
" For Here or to Go" (
tr) Supporting; Karen cuts the patty out of Plankton and analyzes it.
" It's a SpongeBob Christmas!" (
tr) Supporting; Karen tells Plankton that he would get a real present if he wasn't a jerk.
" Chum Fricassee" (
tr) Supporting; Karen is the cashier for the restaurant.
" Move It or Lose It" (
tr) Supporting; Karen helps Plankton sell things to earn money.
" Eek, an Urchin!" (
tr) Distorted voice only; Karen calls Plankton on his cell phone.
" Jailbreak!" (
tr) Minor; she visits Plankton in jail.
" Evil Spatula" (
tr) Supporting; she mixes the ingredients that Mr. Krabs says.
" It Came from Goo Lagoon" (
tr) Minor; she has a mini form built into the submarine.
" Plankton's Pet" (
tr) Major; she gives Plankton the idea to get a pet.
" Company Picnic" (
tr) Deleted scene, credited in voice cast
" Mall Girl Pearl" (
tr) Cameo (non-speaking); she is at the mall on the top floor.
" CopyBob DittoPants" (
tr) Supporting; she has a party with SpongeBob and Plankton, then tries to help teach the SpongeCopies.
" Lame and Fortune" (
tr) Major; she makes the fortune cookies and calms down the crowd.
" Pineapple Invasion" (
tr) Minor; she gives Plankton a push.
" Salsa Imbecilicus" (
tr) Major; she and Sandy team up to help make the town smart again.
" Mimic Madness" (
tr) Deleted scene; in the original storyboard, when Sandy and Plankton are playing chess and SpongeBob mimics them, Karen comes out of the Chum Bucket and laughs at SpongeBob's impression of Plankton.
" Plankton Gets the Boot" (
tr) Major; she kicks Plankton out of the Chum Bucket and he tries to make her jealous.
" Plankton Retires" (
tr) Supporting; she consoles Plankton after his failure.
" The Incredible Shrinking Sponge" (
tr) Minor; she scans SpongeBob and flicks him away.
" Feral Friends" (
tr) Deleted scene; in the rough storyboard, she gave Plankton his food when he got turned into a feral copepod.
" Don't Wake Patrick" (
tr) Cameo (wall form); Karen's wall form is seen in the corner of the Chum Bucket.
" Spot Returns" (
tr) Major; she has a "cute overload" from all the puppies.
" Spin the Bottle" (
tr) Supporting; she asks Plankton about his genie scheme.
" The Legend of Boo-Kini Bottom" (
tr) Supporting; she puts on a show about the horrors of the Krusty Krab.
" Krabby Patty Creature Feature" (
tr) Minor; she gets infected by the patties.
" Grandmum's the Word" (
tr) Supporting; she and Plankton try to have a date when Plankton's grandma interrupts it.
" Bottle Burglars" (
tr) Supporting; Karen is proud of Plankton, and later, she sleepwalks and scares SpongeBob.
" Shopping List" (
tr) Minor; Karen is a chef and tells Plankton not to add the last ingredient.
" Patnocchio" (
tr) Narrates episode; she plays a computer fairy who tells the story of Patnocchio.
" Karen's Virus" (
tr) Major; she gets a virus, and Plankton and SpongeBob have to journey into her hard drive to get it out.
" Girls' Night Out" (
tr) Major; she is one of the Gal Pals.
" Gary & Spot" (
tr) Minor; she sleeps while Spot escapes.
" King Plankton" (
tr) Supporting; she offers to watch SpongeBob's sea chimps for the day.
" Plankton's Old Chum" (
tr) Supporting; she tells Plankton to throw out his old chum.
" The Krusty Bucket" (
tr) Minor; she watches the creation of PlanKrab.
" Karen's Baby" (
tr) Major; she orders a baby computer in the mail.
" SpongeBob's Big Birthday Blowout" (
tr) Minor; she and Plankton dance at the party.
" The Ghost of Plankton" (
tr) Supporting; Karen puts on a funeral for Plankton when he is thought to be dead.
" My Two Krabses" (
tr) Minor; she brings out some chum to make Chum Krabs.
" Hiccup Plague" (
tr) Minor; she catches a hiccup bubble, but shortly after gets rid of it.
" A Cabin in the Kelp" (
tr) Major; she is one of the Gal Pals.
" The Hankering" (
tr) Supporting; she analyzes Mr. Krabs to find Plankton inside.
" Who R Zoo?" (
tr) Minor; she and Plankton are scared by bubble penguins.
" Plankton's Intern" (
tr) Minor; she leaves for vacation and later returns.