Karen Plankton is a recurring character in the SpongeBob SquarePants television series. She is Plankton's wife, a Mark II Surplus UNIVAC. She is the main computer system of Plankton's lab, and is often the source of his plots (although Plankton always takes all the credit). She is voiced by Tom Kenny's wife, Jill Talley.
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 the episode Friend or Foe, it was discovered that Karen was a Security System before Plankton married her.
Karen and Plankton's relationship is a very troubled one. Plankton sometimes does not 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 the episode, 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 Mr. Krabs and often shows very half-hearted 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. Unlike Plankton, however, 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.
Karen is a Mark II Surplus UNIVAC with 256 GBs (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, he mistakes it for Karen.
In the episode Single Cell Anniversary, it appears that she has an "Emergency Mother-In-Law Program," or E.M.I.L.P. for short.
Karen is from Chicago, according to the fact that her portrayer, Jill Talley, is from Chicago, and says that that's how she does Karen's voice, in a Chicagoan accent. Also, in Single Cell Anniversary, Ctrl-Alt-Del doesn't work on her and one of the only computers that it won't work on is some beta versions of Windows 95, when it's code name, Microsoft Chicago, was still in use.
When she is on the wall, her screen looks bigger but when move in her mobile her screen looks even smaller.
Karen makes a cameo in a Fairly OddParents episode called "Love Triangle". After Foop gets bitten by snakes, he ends up in the hospital. In his hospital room Karen is seen as a health monitor.
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.