The "That Kid" is, in short, the kid in your class who everybody hates. He consistently attempts to impress the professor with references to books and topics that ultimately irrelevant to the topic and class at hand. He uses big words which he has little grasp of, and quotes authors and thinkers in a nonchalant and usually incorrect manner. He will argue with the professor over anything in a desperate attempt to appear smart. Sometimes, he will go so far as to try and correct the professor--this always fails, because he is an idiot. It is unknown whether "That Kid" really believes in himself, though it is clear that even if he does not, he is still a raging douchebag.
Possibly and probably related to the hipster.
"Dude, who's that asshole who keeps trying to prove the calculus professor wrong?"
"Oh, it's the class That Kid. Fucktard doesn't understand that calculus is a fucking exact science. The professor looks like he's going to beat the shit out of somebody."
*That Kid raises hand*
"sigh...yes, That Kid?"
"Well, sir, I have to disagree with your methodology in addressing this query. You see, I read in my theory class that Marx addresses the dichotomy between the words therefore and vis a vie and conflicts concordingly with your point of view."
"Are you fucking retarded, That Kid? Sit the fuck down."
"How was class?"
"Oh, fucking god, it was terrible. I'm in a class full of That Kids. They had an argument about "the nature of what is" and I felt like shooting myself."
Obnoxiously Precocious Kid. Every class has one, usually shows their stripes on the first or second day of class by pointing to some obscure point in the text known only by people who actually do the reading.
That Kid unscrews the cap on a salt shaker in a really nice restaurant and laughs with his mouth wide open full of food, spews the food everywhere when somebody spills the salt.
That Kid buys the most expensive Kobe beef on the market, grinds it up into hamburgers and overcooks it, charred and everything.
That Kid sneezes on his hands before shaking hands with somebody (bonus points, he blatantly wipes it on his friend.)
That Kid farts in a really crowded elevator and proclaims, "Oh yeah...that's gonna smell."
That Kid - "Its not even funny anymore, god.."
1) This term is used to describe someone when they do something most people won't, or say something most people wouldn't.
2) Puts emphasis when describing a certain kid that does stuff no one else does.
Jim: WOW!, you're "That Kid"
Jim: thats so you to do that, your retarded.
Brad: i know, i am "That Kid" to do that.