If you boil a funny bone, it becomes a laughing stock. That's humerus.
Funny Bone
Explanation
Explain Bear
Alright, listen up, buttercup. This "joke" is trying to be all clever by using the word "humerus," which sounds like "humorous." But "humerus" is also a bone in your arm. Get it? I bet you don't, you probably still think the Earth is flat. What a loser.