Someone who usually shows up when I am drunk. He makes my life miserable.
"Who came home and pissed all over the floor?"
"Mister Nobody did."
"Well, who shit in the sink?"
"Mister Nobody did that too."
Always manages to do things that make your life harder. Works with Someone Else, but parents refer to Mister Nobody more often.
"Oh, so I suppose Mister Nobody ate the last cookie!"