An artists renderation of Nobody

Real Name: Nobody
Birth: Never
Age: None
Health: None
Family and relatives: Nobody
Impostor(s) Nobody
Death: Never

Nobody (nickname No One) is someone who is very mysterious, and no one knows what he/she looks like. Nobody doesn't make much of any appearances in the other series, yet he/she appears in most games. Nobody usually appears in the background, yet he/she is hard to see. Nobody is a lot like Oxygen, as you can't see them, yet they're still there. Nobody has a major appearance in Mushroom White, which was a VERY short Shame. Nobody also knows certain things you don't know before you do. Like in Everybody Loves Bowser, Bowser's Grandma is a character, yet she died three years ago, yet Nobody still knew this happened. He/She also knows a secret in Mushroom Black. Nobody also bothered to revived Colonel Sanders in Mario & Luigi: Teh 4w3s0m3 Adventure, yet the Colonel's still nowhere to be seen. Nobody also finished Super Mario: Attack of the Randomness. Nobody is also known to like Bacon and ride a Chain Chomp Star. He/she is also known to be the brother/sister of Someone and Anybody. Apparently, in the Pokemon series Nobody actually appears as a person, as he/she is not catchable. (unlike Micheal Jackson...)

Nobody is like the religious gods as well. You can't see him, but he's there.

Conclusion: Nobody cares and knows about stuff that everyone else doesn't.