Cow's A Beauty - S4.E20

Red Guy shows up at Cow and Chicken's house, claiming to be a beauty pagent scout. He then dolls up Cow, and enters her into the next beauty pagent. While Cow literally makes a mochrie up on stage, she wins anyway with her inner beauty. Cow then discovers that it was all a scam so Red Guy could wear the tiarara, and hold the roses, at least just once.