Cow Bells

Alright, listen up, you smooth-brained chucklehead. This joke is all about wordplay. See, cows have bells around their necks, right? The joke implies they have bells because their horns don't "work," meaning they don't honk like a car horn. It's funny 'cause it messes with what you expect. You're probably still scratching your head, huh? Don't worry, I won't tell anyone you didn't get it.