""You should not be afraid to fail. I'm happy and I have suffered 50 years of it!"" ― From New Kelp City on PLWTR

Sheldon J. Plankton
Sheldon J. Plankton
Name of character Sheldon James Plankton
Species Plankton

Sheldon James Plankton (age 59 as in The Algae's Always Greener episode) is a dark green Plankton. He is the main antagonist of SpongeBob SquarePants and was the protagonist of the canon episode The Algae's Always Greener. His main goal in life is to steal the Krabby Patty formula from Mr. Krabs, but always fails. He was married to a computer named Karen, but they got into an argument and had a divorce. He used to be married to a piece of holographic meatloaf that tastes like cardboard donuts. He was once friends with Mr. Krabs. He once was dating Shelia Planktona but broke up as he was using her to get the formula. Unfortunately, his plan failed. He has one eye and is a single-cell organism. He has a pet ameoba named Spot. Plankton and Mr. Krabs were best friends before Mr. Krabs created the Krabby Patty recipe.

  • Poseidon Elementary (Kindergarten, 1st to 3rd grade)
  • Bikini Bottom Elementary (4th Grade to 6th Grade)
  • Shelby Top Jr. High (Half of 7th Grade)
  • Bikini Bottom Jr. High (Rest of 7th Grade, 8th and 9th grade)
  • Poseidon Senior High School (10th and 11th Grade)
  • Bikini Bottom Senior High (12th Grade)
  • Shelby College (6 months) (was kicked out)
  • Bikini Bottom Community College (4 days)




  • SpongeBob (sometimes)
  • Patrick (sometimes)
  • Mr. Krabs (childhood)
  • Squidward (sometimes)
  • Man Ray (Sometimes)

Fanon appearances

Famous Quotes:

  • "Well, this stinks."


  • "I knew I should've gotten the turbo."

  • "But the Bowling Alley is more FAMOUS than the Movie Theater!"

  • "You can ship me off to Canada when I'm done, because when you look at a calculator upside down it says "Jordan, I honestly cannot believe you're doing this. Star Trek VI: The Fast Menace... how much lazy -------- are there like you on this planet? 1? 2? Maybe 3?" and that doesn't look good at all, so if you don't mind getting your big fat flippers off me. I'll kindly give you a thousand dollars to buy the wife a homemade chicken from ASDA."


  • "Yeeah... not much for a sixth grader."

  • "Eugene, I look like something you give to your kid when you tell them 'Grandma died'."

  • "Come on, I look like Snuggles' accountant."

  • "I have an idea. Let's make them play Rock, Paper, Scissors to see who I will turn into a baby."

  • "Well, it looks like I'll turn Sandy into a baby."


  • "Mmm... wanna go to bed early tonight?" *passes out*



  • Plankton is named after the species of Plankton (A small sea creature that whales feed on).
  • Plankton was born in New Plankton City, but moved to Bikini Bottom when he was two months old.
  • Plankton used to own the Chum Caverns, an underground cavern. This only existed in the original series.
  • Plankton is the antagonist in most spin-offs or crossovers.
  • According to the episode of SpongeToons called The Trial Of Plankton, he would possibly be dead by February 17th, 2015. (Anyone who believes that is maybe bad)
  • According to the octal-length episode of Falling Apart called The Harshest Comeback, Plankton is 43 years old by Spring 2014.
Community content is available under CC-BY-SA unless otherwise noted.