Plankton

"Hear me, Krabs. When I discover the formula for Krabby Patties, I'll run you out of business. I WENT TO COLLEGE!"

- Plankton's first quote.

Sheldon J. Plankton, better known as Plankton, is the main antagonist of Nickelodeon's popular cartoon series, SpongeBob SquarePants. He is the owner of the Chum Bucket restaurant who seeks to grow his business by stealing the Krabby Patty formula and eventually take over the world. He was also the main antagonist of the show's first theatrical film The SpongeBob SquarePants Movie and the deuteragonist of its second theatrical film The SpongeBob Movie: Sponge Out of Water.

He was voiced by the famous actor Doug Lawrence.

Role
He works with the help of his sidekick Karen Plankton, a sentient computer who gives him most of his evil plans. He is an evil copepod plankton and the business rival of Mr. Krabs, the owner of the Krusty Krab where SpongeBob SquarePants works. Despite being portrayed as an antagonist in most incarnations, he frequently appears as an anti-hero (an example being the second movie, The SpongeBob Movie: Sponge Out Of Water).

While the Krusty Krab is popular among the sea creatures of Bikini Bottom, Plankton's own restaurant, the Chum Bucket, gets little to no customers. Plankton's plans all revolve around stealing the elusive "Krabby Patty Secret Formula" so he can copy it and make the Chum Bucket popular. He lives inside his restaurant, where he has an elaborate laboratory that contains Karen's system.

Series
Plankton constantly attempts to steal the formula for the Krabby Patty, the delicious burger-like food that is sold in the Krusty Krab. Plankton believes that the Krabby Patty is the reason for the Krusty Krab's success, and that his Chum Bucket would be equally popular if it sold the Patties as well. However, ensuring the success of his business is only the first step in Plankton's plan, which will culminate in him ruling the ocean.

For the events of post-movie seasons (namely season 4 and so on but set in events between first 3 seasons and the movie), Plankton does find alternate means to achieve success, but only temporarily.

Movie
"Oh, grow up! What, do you think this is a game of kickball on the playground? You never had a chance to defeat me, fool! And you know why? (SpongeBob: Because you cheated?) No! Not because I cheated! Because I'm an evil genius... and you're just a kid! Haha! A stupid kid!"

- Plankton to SpongeBob in the movie.

In The SpongeBob SquarePants Movie, Plankton serves as the main antagonist of the film, and it marks the first time when he becomes an alarmingly dangerous and depraved villain of the franchise. He finally manages to steal the formula from Krabs by framing the latter for the theft of King Neptune's crown, resulting Krab to be frozen in ice for six days. This allows the Chum Bucket to become just as popular as the Krusty Krab had been previously. Plankton even comes close to his eventual goal of ruling the sea, by giving away mind-controlling bucket hats free with his Krabby Patties, turning Bikini Bottom into "Planktopolis."

Plankton also hires a hitman named Dennis into stopping SpongeBob and Patrick when they try to retrieve the crown to clear Krab's name. Even when SpongeBob and Patrick finally manage to return the crown to Neptune after defeating Dennis and the Cyclops, this still doesn't stop Plankton as he puts a mind-controlling helmet on Neptune, revealing that the theft of the crown was nothing more than a ruse to lure Neptune under his control and take over the seas for himself. Eventually, Plankton is eventually defeated by Spongebob when he sings the "Goofy Goober Rock" to remove the bucket helmets from all the fish. Plankton is then arrested for his crimes and sent to jail.

Sponge Out of Water
"No, thanks. I'm already part of a teamwork."

- Plankton/Plank-ton refusing to join Burger-Beard.

Plankton returns in the 2015 sequel The SpongeBob Movie: Sponge Out of Water as the deuteragonist. He attempts to steal the Krabby Patty secret formula yet again, but then it disappears when Burger-Beard writes in the magic book to steal it. Then he later becomes an anti-hero, when he begrudingly teams up with Spongebob who was rescuing him from Mr. Krabs and the people of Bikini Bottom falsely accuse Plankton for stealing the formula and Spongebob for "joining his side". Throughout the journey, Spongebob tries to show Plankton the meaning of teamwork, much to his annoyance. Then they go time traveling to keep the secret formula from disappearing. Then Plankton, who was hiding inside SpongeBob's pocket, surprisingly appears to help out with Spongebob, Patrick, and the others to get the Krabby Patty secret formula back from Burger-Beard (the true culprit) as super heroes.

Using the magical book that Burger-Beard stole earlier, Plankton becomes a giant muscle-bound hero (dubbing himself as Plank-Ton). After Burger-Beard defeats SpongeBob, Sandy, Plankton, Squidward, and Krabs, he attempts to escape, only for the muscle-bound Plankton to stop him by lifting up his ship. Embellished with the true meaning of teamwork, Plankton helps SpongeBob create a storm full to bubble to capture Burger-Beard and force him to return the formula.

After kicking Burger-Beard away into a marooned island, Plankton ponders on what to do with the formula, much to Krabs' distraught. However, Plankton decides to give the formula back to Krabs, admitting that keeping things to himself is a selfish thing to do. As everything in Bikini Bottom was turned back to normal, Plankton continues his role as the Krusty Krab's business rival going back to his formula-stealing tricks just to keep things in the status quo.

Battle For Bikini Bottom
Plankton appears in the 2003 video game. He is initially portrayed as if he is the antagonist, but this is to hide the game's real main villain.

In this game, Plankton creates an army of robots to take over Bikini Bottom, but forgets to make them obey him, causing his creations to run amok across the sea bottom. Plankton uses SpongeBob, who is convinced that he caused the robot invasion while role-playing with Patrick, to get rid of the robots, which are led by a Robotic Plankton.

Nicktoons Unite!
Plankton is one of the villains who compose The Evil Syndicate (along with Professor Calamitous, Denzel Quincy Crocker and Vlad Plasmius), the main antagonists of the game. He was charged to harvest energy out of the jellyfishes in Jellyfish Fields for the Doomsday Machine the Syndicate was building, making changes in the Chum Bucket to make it a factory. He also began to kidnap citizens of Bikini Bottom (including Patrick) who didn't go along with his plans. However, the group of heroes assembled by Jimmy Neutron, Spongebob included, managed to free the jellyfishes and defeat Plankton at the Chum Bucket. He retreated to Retroville were he tried to destroy the heroes along with his fellow Syndicate members. But even that failed as his shield was turned off and he was defeated again by Spongebob.

Nicktoons: Globs of Doom
Plankton returns in this game as the only original member to be part of the second Syndicate. He, along with other villains (Nicolai Technus, Beautiful Gorgeous, Traloc and Dib), join forces with the heroes to gather parts for the Vessel of Portentia and defeat the Morphoids. However, he also betrays the heroes at the end when they are about to defeat Globulous Maximus and the villains steal the Vessel. However, he and the others were defeated when Maximus takes them one-on-one at the moon, destroying the Vessel and leaving them in the vacuum of space.

Nicktoons Racing
Plankton appears as the hidden main antagonist of the game. At the beginning, he is making invitations and sending them to Nicktoon characters, attracting their attention to a race. He then arrives at the race in his own car that completely hides his identity. At the end of the race, it was revealed that the prize of the race was a lifetime supply of Krabby Patties, which Plankton's car showed up, revealing that Plankton was the mysterious rider.

Personality
Plankton is an evil mastermind through and through. His plans always involve technological devices and weapons, all for the sake of the formula. His main goal has always been throwing the Krusty Krab out of business. In Seasons 1 to 5, he was completely unable to get any success for his Chum Bucket restaurant (as majorities of his schemes involving attempted theft on Krabby Patty recipe). However, in both events of the first movie and later seasons (which chronologically still set between the first film and and season 5), he was now able to get more chances of success other than stealing the Krabby Patty formula, such as having an attractive restaurant place where the people will come to observe the underground complex beneath both his and Krabs's restaurant. Other examples are putting slogans such as "Chum is Fum" and "Fum is Chum" (where Patrick Star helped him in his slogans until the starfish's both low IQ and literally overheated brain became the setbacks) and one person named Nat Peterson kept coming to buy chum to eat, although he was only doing it since Karen paid him to do so.

All in all, Plankton's small stature, the fact pretty much everyone else in his life looks down on him, and his poverty all cause Plankton to feel very insecure, and even defensive. He clearly suffers Napoleon syndrome, and his desire for conquest stems from his deep-seated desire for respect, and even admiration, both of which are absent from his life. From his childhood of poverty, all the way to his adulthood of feeling neglected, and downtrodden, his bitterness and hatred of nearly everyone has grown, and consumed him, almost molding him into a fully-fledged psychopath. However, traces of empathy are to be found, as he truly loved spot, the amoeaba, and even though he seems to look down on, and belittle Karen, he does actually love her, and Karen returns this love in spite of often snarky to him, much to Plankton's frustration.

Also, it is worth mentioning, due to his small size, and the fact he tends to have huge flaws in all his plans, no one in Bikini Bottom really sees Plankton as a threat, let alone aware with his presence in the town or what will he do. For instance, when Sandy managed to capture Plankton for stealing her fur, the police arrested her instead for her unintentional public nudity and barely notice his presence in spite of him in EXTREMELY close proximity. Most people who knows him and aware with his presence in Bikini Bottom merely see him as a pest and dismissed him as mere annoyance. Only a handful individuals who aware with how dangerous Plankton can be: Mr. Krabs, who acknowledges that if he DID get the the formula, he would make the chum bucket a bigger risk to the Krusty krab that made him vigilant around Plankton (though this doesn't stop Mr Krabs from mocking him); and SpongeBob, whom truly afraid of him and his outlandish schemes, especially since the events of his debut episode where he used a mind control on the sponge and nearly discovered the Krabby Patty's formula in process (though failed, this was enough to alarm SpongeBob about Plankton's villainous qualities and dangers that he can pose to the others).

While Plankton often appears as a bumbling comic foil, he actually can be a real threat under certain circumstances, manipulating others to get his way, and when the odds are in his favour, he can be surprisingly successful, though this success is usually short-lived.

Quotes
"Curses! It's not fair. Krabs is being interviewed by Perch Perkins, and I've never even had one customer!"

- Plankton ranting about Mr. Krabs' success in opening the Krusty Krab 2 and that he never had any customer at the Chum Bucket

"Oh, Karen, my computer wife, if only I could have managed to steal the secret to Krabs' success, the formula for the Krabby Patty. Then people would line up to eat at my restaurant. Lord knows I've tried. I've exhausted every evil plan in my filing cabinet...from A to Y. (Karen: A to Y?) Yeah, A to Y. You know the alphabet. (Karen: What about Z?) Z? (Karen: Z. The letter after Y.) W, X, Y, Z. Plan Z! Here it is, just like you said. (Karen: Oh, boy.)"

- Plankton realizing there is a final plan to steal the formula

"Oh! Oh! Ohhh! It's evil. It's diabolical. t's lemon-scented. This Plan Z can't possibly fail! So enjoy today, Mr. Krabs, because by tomorrow, I'll have the formula. Then everyone will eat at the Chum Bucket, and I will rule the world! All hail Plankton. All hail Plank...! Ow! (SpongeBob: I'm ready! Promotion! Ew, I think I stepped in something!)Not in something, on someone, you twit! (SpongeBob: Oh, Sorry, Plankton. Are you on your way to the grand opening ceremony?) No, I am not on my way over to the grand-opening ceremony. I'm busy planning to rule the world! (Spongebob: Well, good luck with that. I'm ready. Promotion. I'm ready. Promotion.) Stupid kid."

- Plankton telling Spongebob he does not have to go to the grand-opening ceremony while being busy plotting to rule Bikini Bottom

"Time to put Plan Z into effect. Starting at the undersea castle of King Neptune."

- Plankton going to King Neptune's castle to steal his crown and frame Mr. Krabs for the theft

"I got it. I got it!"

- Plankton succeeding in stealing Neptune's crown

"Ding-a-ling. Hey there, old buddy. Freeze. One secret formula to go, please. No, no, don't trouble yourself. I'll get it.Well, I'd like to hang around, but I've got Krabby Patties to make... over at the Chum Bucket. Plan Z, I love ya!"

- Plankton taunting an already frozen Mr. Krabs as he gets the formula and goes back to the Chum Bucket

"(Perch Perkins: Excuse me, Plankton. Perch Perkins, Bikini Bottom News. Can I get a minute?) Anything for you, Perch. (Perch Perkins: All of Bikini Bottom wants to know, how did you get the Krabby Patty?) Well, Perch, before my dear friend Eugene Krabs was frozen by King Neptune... I'm sorry. He confided in me a secret wish. "Sell the Krabby Patty in my absence at the Chum Bucket," he said. "Don't let the flame die out." (fake sobs) By the way, act now and you get a free Chum Bucket bucket helmet with every purchase. Here you go, Perch. (Perch Perkins: Thanks.) Bucket helmets for everyone!"

- Plankton being interviewed by Perch Perkins about how did he get the Krabby Patty and offering bucket helmets to everyone

"Karen, baby, I haven't felt this giddy since the day you agreed to be my wife. (Karen: I never agreed.) Evil Plan Z is working perfectly. Nothing can stop me now! (Karen: Nothing except SpongeBob and his pink friend. My sensors indicate that they're going after the crown. If they make it back, Neptune might discover some fingerprints. Tiny fingerprints. Stubby, tiny fingerprints.) Evil Plan Z is way ahead of you, baby. I've already hired someone to take care of those two. He's a vicious, cold-blooded predator!"

- Plankton assuring Karen that he hired a hitman to prevent Spongebob and Patrick from retrieving the crown

"(Squidward: So you're selling Krabby Patties, eh, Plankton?) That's right, Squidward. And there's a free bucket helmet with every purchase. Care for one? (Squidward: No. You may have hoodwinked everyone else in this backwater town, but you can't fool me. I listen to public radio.) What's that supposed to mean? (Squidward: It means you set up Mr. Krabs. You stole the crown so Neptune would freeze him and you could finally get your stubby little paws on the Krabby Patty formula. [Plankton looks at his hands] It was you all along. But you made one fatal mistake. You messed with my paycheck. And I'm gonna report you to the highest authority in the land, King Neptune!) We'll see about that, Inspector Looselips."

- Plankton prepares to turn Squidward so he can't tell the truth to King Neptune

"No resting! This monument celebrating my glory isn't gonna build itself. Move faster!"

- Plankton pressuring his slaves into building Planktopolis

"Sorry about this calendar. March 14. Wait, that's not right. It should say "The day that Krabs fries!" Guess who's here."

- Plankton plannig to have Mr. Krabs executed by King Neptune

"This is the best seat in the house. All right, Neptune, let's get it on!"

- Plankton before Mr. Krabs' execution

"Oh, yes. Well done, SpongeBoob. (Spongebob: Sorry to rain on your parade, Plankton.) Oh, don't worry about me. My parade shall be quite dry under my umbrella!"

- Plankton sarcastically complimenting Spongebob before mind-controlling King Neptune

"(Patrick: What happened?) (SpongeBob: Plankton cheated.) Cheated? Hold on there, baldy. Oh, grow up. What, you think this is a game of kickball on the playground? You never had a chance to defeat me, fool! And you know why? (Spongebob: Because you cheated?) No, not because I cheated! Because I'm an evil genius. And you're just a kid. A stupid kid!"

- Plankton mocking Spongebob and calling him a stupid kid

"His dance moves are impressive, but I'm in control. Seize him!"

- Plankton ordering his slaves to capture Spongebob only for them to be blasted away by the latter

"My precious helmets!"

- Plankton yelling in defeat while Spongebob frees the mind-controlled Bikini Bottom residents

"Come on, I was just kidding. Come on, you guys knew that, didn't you? With the helmets and the big monuments...Wasn't that hilarious, everybody? I will destroy all of you!"

- Plankton's last words in the first film before he is sent away to prison

Trivia

 * Plankton found Mr. Krabs' life to be worse than his life, when he experienced it in The Algae's Always Greener and Spy Buddies. In The Algae's Always Greener, he found lots of reasons that make Mr. Krab's life difficult:
 * SpongeBob is always asking him for a Weekly Performance Review on Tuesday and makes a teensy little temper tantrum if Plankton refuses. He also keeps yelling "SOILED IT! SOILED IT! SOILED IT!" when he accidentally gave a customer a large soda when the customer wanted a medium soda.
 * Squidward, the lazy, grumpy, pessimistic worker at the restaurant, complains to Plankton that he doesn't want to work with SpongeBob. Later, when Plankton put him in charge of fry cooking, a customer got angry because the Krabby Patty that Squidward cooked was very ugly, disgusting-looking, and hideous.
 * Pearl, his virtual reality daughter, throws a big temper tantrum because she doesn't get more than $1.
 * Krabs tries to steal the Krabby Patty formula (which Plankton actually does in the show's reality), and Krabs NEVER gives up like he does.
 * In the first movie (The SpongeBob SquarePants Movie), Plankton was a lot more evil and depraved than he was in the series as he ultimately grown into alarmingly dangerous threat to the entire ocean. In the said movie, he stole King Neptune's crown, frames Mr. Krabs for it, sends Dennis to kill SpongeBob and Patrick rather than merely get rid of them, enslaves Bikini Bottom (which also includes not allowing his slaves to earn a single rest or break and just work nonstop) and shows excitement and joy when Mr. Krabs is going to be killed. He also enslaved King Neptune, in which gave him a potentially powerful asset in conquering the whole ocean and the world. This is likely the only time Plankton came close to being Pure Evil, making it his most evil moment in the whole franchise.
 * This however, ultimately outclassed by Burger-Beard in the sequel, as aside managed to instantly steal the Krabby Patty recipe simply by rewriting the magic book that records everything that occurs in the ocean (especially events in Bikini Bottom includes conflict between Plankton and Krabs), the pirate was able to destroy Bikini Bottom and render it into post-apocalypse state in an instant. Even in order to defeat Burger Beard, it took the superpowered SpongeBob, Sandy, Patrick, Krabs, Squidward, and Plankton himself to defeat him.
 * Early in the series, Plankton is considered a true villain. Later, as Krabs becomes more dramatically greedy (said greed ultimately drove him insane) and Plankton becomes less dramatically evil and less of a genius, the role of the main villain of the series becomes more debatable as lots of people think Mr. Krabs is evil. Plankton also acknowledges this himself when he begins to question whether he or Krabs is truly evil.