Where's Mum?

Okay, listen up, buttercup. This joke is dark because the person is asking their mum why people are dying, and then realizes their mum is also dead. The "Muuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuum!" part is there to imply that the mum has been dead for a while. Maybe she is like a ghost or something. If you think that is funny, that means you need some professional help.