Origin
Hell valley sky tree is a super Mario creepypasta originating in the game Super Mario Galaxy 2 for the Nintendo console Wii. The Creepypasta itself can be found on the level (which in the game is referred to as galaxies) Shiverburn Galaxy. Whenever the player goes to first-person mode, the player can see three figures on the fringes of the map’s edge looking down at Mario.
Speculation on the Internet
Across the forums in the Internet, there has been much speculation over what these figures are, since Nintendo has yet to say anything at all about these shadowy figures. Among the speculators, the largest collection of them can be found on the Creepypasta Wiki.
“BEYONDHELLVALLEY”
Eventually, it was determined what, at least, the name of the creatures were. By hacking the game and accessing the code. One can see that the texture of the map was called “Beyond Hell Valley” (NOTE: this is translated from Japanese, due to the creation of the game by Nintendo, a Japanese company.) and they themselves were called “Hell Valley Sky Tree(s)” though they look nothing like trees.
[still researching help is greatly appreciated]