Slender Man

Slender Man is a unknown humanoid who haunts the Mushroom Kingdom. He has been repeatedly been around there for 3 months now and has already killed 13 toads. There have been notes nailed onto trees saying; "MARIO!". It is possible he is after Mario, but some wise guys say he just wants his autograph. After 2 days, those toads have gone missing.

History
Slender Man has a history of killing many humans on Planet Earth, all around the globe. There have been many pictures and videos taken off him, but somehow, were made distorted. Humans of Planet Earth believe that he could be an extraterrestrial from another planet. Some experts say that he seems to have tentacles on his back and may use them to kill his victims.

Mushroom Kingdom
It is currently unknown why he is at the Mushroom Kingdom and how he even got there, but all that is known is that he is murdering toads and is out to get Mario.