Karen Plankton

Karen's personality is made up of her four computer chips: smart, evil, snarky, and empathetic. Due to her empathy chip, Karen normally acts like a nice and loving person when she and Plankton are in a good mood. However, due to her evil chip, she is also evil enough to be a villain (possibly more so than Plankton). Plankton has a filing cabinet of evil plans that Karen reminds him about. Since she writes the majority of his plans, it can be assumed that she wrote these as well. They are in a descending order from harmless to sinister, the worst being "Plan Z" — the only scheme to result in Plankton successfully stealing the formula and using it to his advantage. This plan involves enslaving everyone in Bikini Bottom, forcing a frozen Mr. Krabs to watch the town descend into evil and be killed by King Neptune, and sending a hitman to murder SpongeBob and Patrick. Karen uses her mind-control abilities to enslave the citizens and is one of the only townspeople not to be a slave. This shows that she is just as cruel and sinister as her husband, if not more. Her darkest side is also shown in Plankton's Good Eye where she encourages Plankton to be evil and hates his good side. Other instances of her dark side include using her lasers on Plankton in multiple episodes and assisting him in his plots in nearly every story focusing on them.

Appearance: a robot woman with grey skin, blue hands, and a blue TV for head, her screen is mainly just a green line that moves whenever she speaks, but sometimes it would change to a face to show more expressions,