Horse Butt Mechanic

Okay, listen up, you smooth-brained chucklehead. So, you see, there's a guy with his hand way up a horse's rear, right? Now, the punchline twists it by suggesting it's not some weird accident, but rather, it's just an Amish mechanic doin' his thing. You know, because Amish folks are known for working with animals. Get it now, dummy?