A man / boy who, upon hearing you tell of an achievement or tale, will always claim to have done the same but bigger, better, or faster than you.
"I built this huge joint
last night. We used almost a whole pack of papers
"oh yeah, well i built one, like, last year. At, like, my cousins house, who you don't know, and we used, like, two packs of papers!
"Yeah. Sure thing, Mr Three Balls."