Karen Plankton is a recurring character in the SpongeBob SquarePantstelevision series. She is Plankton's computer wife. She is the main computer system of Plankton's lab, and is often the source of his plots (although Plankton doesn't listen and always takes all the credit).
Karen usually manifests on the large-screen computer in Plankton's lab, but sometimes acts through a portable wheeled computer. She was first shown in the episode Plankton!, although in her first appearance she was simply Plankton's talking computer and would not be established as his wife until later on. In Friend or Foe, it was discovered that Karen was a Security System before Plankton had married her.
Karen is a Mark II Surplus UNIVAC with 256 GB (Gigabytes) of RAM, and it has been mentioned that she was a security system before marrying Plankton. In "Goo Goo Gas," when Plankton sprays her with the gas, Karen is turned into a calculator. In "All That Glitters", a monitor that looks exactly like Karen in her portable form is seen in the hospital and in "Shellback Shenanigans," Plankton mistakes it for Karen. In "Single Cell Anniversary," it appears that she has an "Emergency Mother-In-Law Program" – or E.M.I.L.P. for short.
Karen's personality varies from episode to episode, but generally she seems nice, but on some occasions she is considered evil. So far, her most evil appearance is Plankton's Good Eye because she encourages Plankton to be evil and hates his good side. In Single Cell Anniversary, Plankton tells SpongeBob that one of the things that Plankton and Karen like to do is "take long walks on the beach, and ... talk about ... Our dreams of concurring all of Bikini Bottom and become supreme overlords of all creation and to trample our enemies beneath our feet."
She is not just evil; however, she is also a loving wife. In Karen 2.0, she got angry at Karen 2 for rolling on Plankton.
She has been sad in the episode Karen 2.0 when Plankton replaced her.
In almost all of her appearances she has been angry at Plankton.
Karen and Plankton's relationship is a very troubled one. Sometimes, Plankton doesn't consider her his true soul mate, and explains to her in "Enemy In-Law" that W.I.F.E. stands for "Wired Integrated Female Electroencephalograph." The two frequently argue, and Karen is often very bossy, sarcastic, and cynical to her husband, having nagging software installed in her. She also thinks Plankton's first name (Sheldon) is hilarious, as shown in "Plankton's Army," which is why Plankton had to unplug her after she kept making fun of his name, even when he told her to stop. Karen is often indifferent to her husband's plots to defeat Krabs and often shows very halfhearted dedication to his plans for domination over others. Despite their differences, Plankton has said that marrying Karen was the greatest thing that ever happened to him, the second being his Evil Plan Z succeeding. However, unlike Plankton, Karen shows some degree of dedication for her husband. This is evident whenever she appears, often showing it in the form of assistance in Plankton's schemes, consoling him whenever he's down, and even crying upon Plankton when he told her what W.I.F.E. stands for. It is most likely that Plankton either ignores, or cannot register the acts of kindness that Karen often performs for him, resulting in their various feuds.
Karen is, in some ways, smarter than her husband. A running gag in the series is that while Plankton is contemplating his plans in his lab, Karen will suggest a route of action to him, and he will either not heed her plans or take credit for them.
F.U.N. - She tells Plankton how to get the formula.
Enemy In-Law - She nags Plankton. She also zaps him with a laser at the end of the episode.
So far, no children of Karen and Plankton are known.
She and Plankton have lived in the Chum Bucket throughout the entire series.
Built or Born?
One of the biggest disputed facts in SpongeBob is whether Karen was built or born. Plankton has said or implied on multiple occasions that she was built. But in The Algae's Always Greener he stated "Your parents must have been like, part computer or something." Implying she has parents. This was the beginning of the different "origins" for Karen.
Other evidence supporting that she was born is the fact that her parents were actually created. E.M.I.L.P, Karen's mother made an appearance in Single Cell Anniversary. Fredrick, Karen's father was created by a fan and has only been seen in a Nickelodeon Magazine.
On the other hand as stated above Plankton has said or implied that he built Karen. One of episodes that most supports this is Karen 2.0, where Plankton replaces her with an updated version.
When Goo Goo Gas was used on her, she became a calculator, but Mr. Krabs once said (referring to his cash register), "No! I got it when it was just a little calculator!". This could mean that the cash register that Mr. Krabs has could turn into a big computer like Karen for some unknown reasons.