Planktonine is Plankton's girlfriend. She was kidnapped by Lester Simpson in World 6 the original. She was later kidnapped by Lauren Tiniathan along with Plankton in World 1. She was later kidnapped by Sharpay Finster in World 2 along with Plankton. She did not appear as a playable character in the Theory of Time, but will appear again in the Theory 6. One of her personalities is kiddy. She giggles in situations that are not humorous. She has the same brain mixed with Marshmallow from the Annoying Orange series, but Marshmallow talks more prettier. While not adventuring, she works as a lawyer. Ever since Supernanny: The Theory International, she is able to purchase a lawyer outfit for jewels. She is portrayed by Maria Menounos in the original theory game, and Ariana Grande otherwise.
Her appearance is the same as the ten-foot atomic-powered plankton, but almost half the size, bigger than that, wears sports pink bows, has makeup on her face, and long eyelashes.