'Frozen' Oscar Winner -- My Statuette is Super Cocky

Robert Lopez struck a pose that said ... "SUCK IT" ... right after his Oscar win put him in an exclusive club with the likes of Mel Brooks and Whoopi Goldberg.

Gotta love the bravado ... Lopez flashed his big swinging statuette to reporters and photogs backstage shortly after he and his wife won the Oscar for Original Song for "Let It Go" from "Frozen."

Robert's got reason to brag ... he's now one of 12 people to ever earn the elusive EGOT -- winning an Emmy, Grammy, Oscar, and Tony -- and he did it in 10 years ... way faster than anyone else.