Flats the Flounder

"Well, I like to kick people's butts."

- Flats' first lines.

Flats the Flounder is the main antagonist of the season 3 Spongebob episode The Bully. He is a brutish bully who has a hobby of injuring others and attempts to kill Spongebob Squarepants several times.

The Bully
Flats is first seen as Mrs. Puff's new student. He takes a seat next to Spongebob, but when the latter introduces himself, Flats threatens to kick his butt. Spongebob initially takes it as a joke, but Flats rips his chest hair off and his chest spells "I MEAN IT", Spongebob immediately realizes Flats means it.

Mrs. Puff then asks for a volunteer to draw a basic four way intersection and chooses Flats, who then draws various diagrams of him beating Spongebob up. Although it terrifies Spongebob, Mrs. Puff is instead impressed by his "creativity".

After class, Spongebob hides in the bathroom, but is promptly found by Flats. Spongebob attempts to strike a conversation, but Flats simply states that he will kick Spongebob's butt "twice as hard", before leaving.

Spongebob picks up a nearby ringing phone and discovers Patrick on the line. When Spongebob asks for Patrick's help, he soon realizes that Flats is inside Patrick's house and they are old community college friends. Patrick then hangs up, but not before claiming that Flats has to leave, since he is going to kick somebody's butt.

In a state of panic, Spongebob reports Flats to Mrs. Puff, who is appalled and agrees to speak with Flats. During recess, Mrs. Puff tells Spongebob that she spoke to Flats, and he said that he is from a place where kicking someone's butt means to befriend them. However, while explaining, Spongebob and Flats make eye contact, and sees Flats making a sand replica of Spongebob before kicking it down.

Spongebob runs out of school campus and bumps into Flats' father and informs him of Flats' behavior. However, Flats sees this and chastises his own father for talking to strangers. The two then leave, Flats' father afraid that his own son will kick his butt.

Spongebob flees into the city and hides in a trash can, but is confronted by Flats in a garbage truck, who then chases Spongebob. While running, a banana peel falls out of Spongebob's trash can and Flats runs over it, causing his truck to flip over and crash and critically injuring Flats.

He wakes up in the hospital some time later, and is informed that Spongebob perfomred five ours of CPR. Moved, Flats claims he will remember this kindness while kicking Spongebob's butt. Spongebob flees to his house, but Flats arrives and kicks his door down seconds later.

Spongebob puts a blindfold on and prepares himself for the assault. Flats punches him in the chest, but Spongebob does not feel it. He removes his blindfold and realizes that his spongy body is absorbing the blows.

Spongebob then goes to work, plays Go Fish with Gary, goes jellyfishing, uses the restroom, and even goes to sleep, all while Flats is punching him. Spongebob wakes up the next day, pours a bowl of cereal, and goes to school, still being punched by an exhausted Flats. Shortly after Spongebob takes his seat, Flats passes out from exhaustion, and Spongebob's classmates cheer for him.

Spongebob stops their cheering, holds his fist, and claims that Flats is the true victim, for he went down a violent road to nowhere. Mrs. Puff the enters the class, and after seeing Flats' unconscious body and Spongebob's closed fist, she becomes enraged that Spongebob "beat up a new student" and claims she will kick his butt.

Trivia

 * Despite being enrolled in boating school, he was seen perfectly able to drive a dump truck.