Dead Eye Plankton was the main antagonist in the episode "Pest of the West." He was defeated when SpongeBuck squashed him, and he's also one of Sheldon J. Plankton's ancestors.
Dead Eye Plankton looks similar to his great-great grandson, Plankton, except he has a handle-bar mustache, and wears a red bowtie and a stovepipe top hat. Even though he is quite small, everyone was still scared of him except SpongeBuck SquarePants.
Dead Eye Plankton was born to an unknown Mr. and Mrs. Plankton.
According to himself, Dead Eye went westward and took over a town called "Bikini Gulch." He robbed the town, pulled Pecos Patrick's pants down, and made all the pretty girls cry. He then renamed the town, "Dead Eye Gulch." He desired the deed to the Krusty Kantina. He has also killed numerous sheriffs or run them out of town.
One day, SpongeBuck SquarePants came to Dead Eye Gulch to be a fry cook, but was given the sheriff's position due to a misunderstanding. Dead Eye went to the saloon to get Mr. Krabs' mortgage, but was interrupted by SpongeBuck. Dead Eye ran him out of town too, and sped up his plan to take the possessions of everyone in town. Later, SpongeBuck came back with the help of Pecos Patrick. He and Dead Eye had a fight a noon, but SpongeBuck defeated him by simply stepping on him.
Later on, the citizens of Dead Eye Gulch rejoiced as they realized that Dead Eye could be stopped just by easily squishing him. Mr. Krabs capitalized on this and set up a business where citizens (like Western Pufferfish) could stomp on him.
Dead Eye Plankton was sentenced to prison, but eventually escaped. If he was recaptured, then he was eventually released. He went on to have at least one child, a son.
When Pecos Patrick stated that he was from the East, this could mean that rich people from the East Coast are usually more overpowered then the Western people at the time.
Dead Eye makes records for "driving a sheriff out of town." In "Pest of the West," he was only a few seconds off his record.
Burger King made a toy version of him. The differences between the toy and the character are that the toy's mustache is smaller, does not have a bow tie, and its hat is more like a top hat than the character.