Memorable for his constant scheming to steal the Krabby Patty formula and the wretched slop he attempts to sell as food at the Chum Bucket, Plankton is the main antagonist from the widely beloved SpongeBob SquarePants cartoon series. While Plankton initially seems to lack depth due to his limited ambitions, a lot of thought was put into him as a character and his abounding quirks—from being married to a computer to his telling rendition of SpongeBob's "F.U.N. Song."

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With over two decades of stories, SpongeBob SquarePants has revealed a lot about Plankton over the years. And although viewers know of his extensive history of failed attempts at stealing the Krabby Patty formula, many compelling aspects of Plankton's character go unnoticed.

9 His Real Name Is Sheldon

Plankton unknowingly standing in front of a light-up sign of his first name

While the main antagonist of the SpongeBob SquarePants series is typically referred to as Plankton, the planktonic copepod's real name is Sheldon J. Plankton. Even though his wife Karen calls Plankton by his first name throughout the series, he expresses fleeting discomfort when Karen refers to him by his first name in "Plankton's Army."

Sheldon is not a name that conjures up fear or worry, which is likely why Plankton doesn't like to be called by it. Although the name itself has no deeper significance, it does serve to remind both viewers and characters who have perpetually been antagonized by Plankton that he is just a small, erudite creature with a Napoleon complex.

8 His Rivalry With Mr. Krabs Goes Back Many Years

Young Plankton and Mr. Krabs fighting

The ongoing frenemy dynamic between Plankton and Mr. Krabs is perhaps one of the most notable aspects of the series, but viewers often forget that there was a time when the two were the best of friends. Their friendship began as soon as they were born, and the pair were once inseparable.

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However, this bond was put to the ultimate test when they decided to go into business together after their favorite burger joint shut down. The two quickly got into a fight, leading Mr. Krabs to claim sole ownership over their mentor's burger recipe. As a result, Plankton swore vengeance and has tried to steal the formula ever since.

7 His Voice Actor Has Played A Pivotal Role Throughout The Show's 23 Years Of Production

Doug Lawrence and Plankton

As a character, Plankton has a deep, resonating voice that fits him so well that fans could not imagine it any other way. While this much is undeniable, most viewers don't have a true grasp on how central a role Plankton's voice actor (Doug Lawrence, known professionally as Mr. Lawrence) has played in the cartoon's conceptualization and production.

In addition to providing the voices of memorable characters like Larry the Lobster, the fish anchorman, and Fred (of "My leg!" fame), Lawrence has also worked as a writer on the series for much of its airtime.As well as lending his voice and writing talents to SpongeBob Squarepants, Doug Lawrence has also directed episodes of the show and worked on the storyboards for The SpongeBob Movie: Sponge Out of Water.

6 He Has A Dog

Plankton's pet Labrador Retriever in his laboratory

Although Plankton openly detests many types of animals across the long-running cartoon series—something that is most notably observed in his unbridled fear of Mr. Krabs' daughter Pearl—it is revealed in "Plankton!" that he has a pet Labrador Retriever.

The dog is only featured in a handful of episodes and primarily appears so Plankton could make the pun of having both a lab and a laboratory. Despite this, the fact that Plankton has such a sociable, loving dog suggests that there is a softer side of him that fans rarely see because of his preoccupation with attaining vengeance against Mr. Krabs.

5 He Is Actually Quite Well Educated

Plankton under a magnifying glass, saying one of his most notable quotes

Another aspect of Plankton that viewers often overlook due to his one-track motivations is that he is well-educated. Despite failing to steal the Krabby Patty formula time after time, Plankton is frequently recognized as the smartest member of his predominantly hillbilly family.

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In fact, one ongoing (albeit less memorable) gag that spans the series is Plankton exclaiming that he went to college after his plans are foiled by Mr. Krabs and his employees. This is especially comedic, considering he and Mr. Krabs briefly attend Bikini Bottom University in Season 9, suggesting they are essentially equal in terms of academic achievements.

4 His Height Inconsistently Changes Across The Series

Plankton getting his mug shot taken while standing next to a ruler in Spongebob

Although there are several moments when SpongeBob can easily pick up Plankton and hold him in the palm of his hand, this sense of scale is not consistent throughout SpongeBob SquarePants. This is most noticeable in later episodes of the series when either SpongeBob's hand appears to be smaller than normal or Plankton is larger than he is in earlier seasons.

A similar discrepancy can be seen in the episode titled "Call the Cops" as Plankton's mug shot is taken. In this particular scene, there is a ruler next to him that indicates he is roughly 4 inches tall (or 9 inches tall if you count his antennae).

3 He And Mr. Krabs Are Exactly The Same Age

Mr. Krabs and Plankton celebrating their shared birthday

Much of why Plankton and Mr. Krabs were such close friends from an early age is because they were actually born on the same day: Nov. 30, 1942. Even though this date does not possess any deeper canonical significance in the show since little emphasis is placed on the characters' "real" ages, knowing that Plankton and Mr. Krabs spent their youths and much of their adolescence celebrating their birthdays alongside one another speaks to why the pair was inseparable before their individualist, capitalist greed got in the way.

2 He Is Not Actually Green

Plankton in his underwear

While it makes sense to assume that Plankton is green since there is no clear indication that he wears any sort of clothing, that isn't actually the case. It has been revealed that Plankton actually wears uniform green suits that give him his signature pigment.

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In fact, Plankton is actually a pale shade of pink, which viewers only fleetingly see when Karen removes Planton's green suit to expose a shade of pink that is softer in hue than Patrick's. Such logic actually adds up, especially in consideration of how Mr. Krabs is a similarly soft shade of red underneath his vibrant shell.

1 He Has Tried To Steal The Krabby Patty Formula Over 1,000 Times

Plankton carrying away the Krabby Patty formula

Although Plankton is incredibly memorable as a character due to his countless failed attempts to steal the Krabby Patty formula, many viewers don't realize the sheer magnitude of his failure. In the cartoon's 10-year anniversary special, "Truth or Square," it is revealed that Plankton has tried and failed to steal Mr. Krabs' formula 1,003 times—a number that has surely gone up immensely since the episode aired in 2009.

While this number may not surprise viewers since this subplot has been a mainstay of the series since its early days, it speaks volumes in regard to Plankton's unwavering perseverance as well as how he consistently falls slightly short of achieving his long-term goal. Perhaps Plankton should be commended for his commitment to reaching his goal, if only it wasn't a morally questionable goal.

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