Karen 2 was a computer that Sheldon J. Plankton built to replace Karen Classic in the episode, "Karen 2.0." She serves as the main antagonist of the episode, and it marks her only appearance in the series due to her exploding at the end of the episode.
Karen 2 is more evil and also had a different design from the original Karen. Unlike Karen Classic, she did not have arms (even though she used a utility arm to access the Chum Bucket power grid). She was destroyed by Karen Classic at the end of the episode when Karen punched her because she ran over Plankton by accident, as she wasn't paying attention where she was going, and because Karen smacked Karen 2 in the screen (Face).
She was 'rebuilt' by taking the glass and electronics out of her screen and by Mr Krabs putting it on Squidward's face to help bring in more customers (Mr. Krabs said that kids love robots). Squidward said: "Hello, welcome to the Krusty Krab. May I take your order? Beep beep..." He also mentioned he wouldn't mind to have his face in a toilet.
Many people say that Karen 2 and Karen could be sisters, but this is unconfirmed. However, Plankton created them both, so this could be a fact.