He looks like Plankton, but he always wears a toque blanche.
He first appears on top of the Cookie Bucket when SpongeBob knocks on the door. He calls down to SpongeBob. He mentions that the reason he is on the roof is to keep watch for the thief of his Secret Cookie Formula. However, while he was distracted the cookie thief, Karen took the formula. She runs off and Plankton runs after her.
Mr. Krabs appears and says that his boss, Mr. Plankton does not like when people don't buy cookies.
SpongeBob grabs the attention of the heroes and Patrick Man sets Karen down, who runs away. Plankton mentions that she is doing so.
It is unknown how similar his backstory is with the main universe Plankton.
What is known is that at some point, he opened up the Cookie Bucket and hired Mr. Krabs.
It is unknown if he invented Karen, but it is unlikely since she does not seem to refer to him as Plankton.