oaker
A guy who thinks he's the king of the court but gets tossed out of real life like a soggy pizza.
"You're an oaker? I've seen dogs with more brain cells than you.", from a gym teacher
"That guy thinks he's a legend. He's an oaker.", said by a kid who got kicked out of the game
My cousin is an oaker. He still thinks he's a football star even though he can't spell 'football.'