Karen

Giant Screen Karen

Mobile Karen

Medieval Karen

Karen Plankton is one of the main characters. She is the sentient computer system of Sheldon Plankton's laboratory, as well as his sidekick, best friend, and wife. She usually comes up with plans to steal the Krabby Patty Secret Formula, which Plankton tends to think are his own ideas. Karen was introduced in the episode "Plankton!" along with her husband. As revealed in the "Friend or Foe?" special, Karen was just a security system when she started dating Sheldon. Karen has a mother named EMILP, who is seen in "Single Cell Anniversary" as a computer program. Her father has never been seen in the series, but appears in an issue of Nickelodeon Magazine.

She has a Chicago accent, in contrast to Sandy the Squirrel's Southern accent, and Plankton's Lithuanian-Estonian one.

In Karen's first appearance, Plankton planned to use her analyzer program to decipher the Krabby Patty formula. In the episode: Fear of a Krabby Patty, she had eyes, a nose, and mouth telling Plankton "I heard this joke before". Karen and Plankton argue amongst themselves for Plankton had installed a nagging software to Karen. Karen finds Plankton's first name -Sheldon- funny, as we see in Plankton's Army

Plankton refers to Karen sarcastically as "the wind beneath my wings" when he has had enough of her nagging on one occasion in the episode Krabs a la Mode.

In the movie, Karen had a minor role. This was the first time Karen is seen in an updated form; Karen is smaller and now has wheels. Plankton also installed a button into Karen that would help him succeed in Plan Z and take over Bikini Bottom She also had a Diary That Was Published By The Bikini Bottom Publication Book Society, Her Diary Was Called The Life Of Karen Plankton.

Design/Changes

She has a green wave on her screen to tell in which frequency she is speaking at. She has many buttons below the screen. Clem, and the rest of Plankton's Cousins thinks that she's pretty. She has a built in analyzer, which can tell the ingredients in an item. In the episodes Bucket Sweet Bucket, Friend or Foe? and Komputer Overload, as well as The SpongeBob SquarePants Movie, she was seen as a small computer which could move. And in the episode Goo Goo Gas, she is a baby calculator. As a baby calculator, the only known word she said was, "Hello."

Quotes

"Seaweed: 50% Sea, 50% Weed. (Later towards the end of the episode) Plankton: 1% Evil, 99% Hot Gas." (Plankton!)
"I heard this joke before!" (Fear of a Krabby Patty)
"Just blink." (Komputer Overload)
"Aw, I think you're just being overlydramatic." Plankton's Army)
"So, typical day of failure, I see, huh darling?" (The Algae's Always Greener)
"Don't you dare!" (Single Cell Anniversary)
"I never agreed." (The SpongeBob SquarePants Movie)
"I suppose it would, if I had one."
"SHELDON!! HA HA HA!"
" The self-destruct coin slot has been activated. Ten seconds till detonation." (Imitation Krabs)
" Loading E.M.I.L.P."
"Here's your stir fry, little man!" (Karen 2.0)