Puffed Up - S1.E13

Two pigs take turns taking a deep breath and holding it, puffing themselves up to see which pig is bigger. One takes such a big breath that the other pig leaves and returns with a cork to plug up the first pig's mouth. When the first pig starts floating like a balloon, the second pig uncorks the mouth, and the first pig deflates and flies around, landing in a splat. The second pig drops the cork and walks away.