Lee Corso (left, wearing Oklahoma mascot head) picked the Sooners to a chorus of boos on ESPN's College GameDay. ESPN officials estimated the crowd to be around 18,000 people, a show record. (Photo by Ross Taylor)

Even Lee Corso’s pick of Oklahoma to beat Mizzou couldn’t put a damper on the atmosphere at Francis Quadrangle Saturday morning.

The estimated 18,000 fans—a new GameDay record, breaking the previous mark set at Nebraska by about 3,000—were raucous throughout the three-hour GameDay show, which began at 8 a.m.

But the most impressive part of the crowd may have been the sheer number of signs brought by fans. And a high percentage of those signs were clever, or, at the least, made you laugh. Check out some of those signs after the jump (all sign photos were taken by JJ Stankevitz for KBIA Sports Extra).

(The final line is "The Who Cares?")

We didn’t get photos of all the signs—there were a few other good ones out there—but a common theme between a number of signs was Justin Bieber: