Hell Valley Sky Tree

The Hell Valley Sky Trees are a mysterious, and very rare race of creatures that can only be found within the Shiverborn Galaxy, within the game Super Mario Galaxy 2. Their names along with where they live are only ever found out through searching the game files.

Description
Despite their names, these creatures hold very little resemblance to any known flora. They are black in coloration, some figures with long arms whereas some don't, and their eyes seem to make that area of their heads transparent, able to see through and passed them.

They're found very rarely in isolated areas of various worlds, their most prominent area being that of the Shiverburn Galaxy, within an area known as Beyond Hell Valley.

Very little is truly known about them.