Nickname: S.K.
Real Name: He never told anyone
Species: Shadow Being
Favorite Food: Anything spicy
Favorite Drink: Anything with lime
Friends: Midna Koopa, Multiplo, Shadoo
Likes: Multiplo (his best friend), interviewing (for some strange reason), The Pit of 100 Trials (he lives at the bottom now that Bonetail's gone).
Dislikes: M.K. (he won't talk about it), Bowser (who doesn't these days), that one Red Chomp (he almost ate him), and pretty much anyone else (he just hates people).
First Appearance: MIDNA KOOPA interviews MARIO
Personal Quote: "ANSWER THE QUESTION, PUNK!"
Favorite Minion: Anything dark (Dark Koopa, Dark, Boo, Dark Wizzerd, etc)
Favorite Villain: Shadoo
Appearance: Looks like an average human male, but his whole body is dark gray. He has sharp claws, spiked shoes, and a weird crown. His crown looks like a normal king's crown from the front, but from the side, I can only describe it as kind of wavy at the top instead of pointy. He always has a grim look on his face.

The Shadow King is the king of part of the shadow realm, but he never talks about it in the studio. Not even his best friend Multiplo knows much about him. The only thing that is certain is that the Shadow King is not pleased with M.K. Perhaps something happened between them? We may never know...