Monday Night Countdown star Jason Kelce donned a Fred Flintstone costume and joined the Bills mafia in a tailgate before the game against the New York Jets on Monday, Oct. 14.

Jason Kelce dressed up as Fred Flinstone and drank out of a bowling ball while tailgating with Buffalo Bills fans on Monday, October 14 ...

A character depicting Fred Flintstone is seen at a pumpkin exhibition in the garden of Ludwigsburg Castle in Ludwigsburg, southern Germany, on August 24, 2023. The pumpkin exhibition is themed ...

Kelce, rocking a Fred Flintstone costume, didn’t just stand by and watch the fun -- he dove right in while taking a shot out of the iconic Pinto Ron bowling ball, a Buffalo tailgate staple.

Mack Hollins’ outfits are one of the best parts of Buffalo Bills games. The wideout and special-teams ace showed up for Sunday’s game with the Denver Broncos looking like a cartoon character.