Following the success of Super Mario Galaxy, Nintendo released a sequel in 2010 that brought back the physics-based fun of the original. To stop another nefarious scheme by Bowser, Mario and Luigi travel a new system of galaxies, saving various creatures and making friends in the process. These new locations opened the door for more creative level designs.

One example is in the Shiverburn Galaxy. As the name suggests, the galaxy is a mixture of ice and lava, meaning players need to be careful not to fall into lava as they slip and slide across the ice. While exploring this dangerous level, there are mysterious beings in the background staring at the player, beings that the game never acknowledges or explains. Due to this lack of information, fans online have come up with their own explanations, creating stories that range from informative to frightening.

RELATED: How Many Worlds Are There In Super Mario 3D World?

Known as the HellValleySkyTrees, many became aware of these strange beings thanks to a Creepypasta exploring the mystery. What what makes them so strange and engaging is the small amount we do know about them. For example, the name "HellValleySkyTrees" actually comes from their in-game file name. Also, since the figures are a part of the background textures, their properties also make them more mysterious and peculiar.

Super Mario Galaxy 2 shows three of these figures overlooking the cliff, but there's a fourth out of sight. Even with flight or moon jump hacks, players can't reach them. In reality, the figures are also gigantic -- far larger than Mario or Luigi, something that only adds to their lore. Between their size and mysterious nature, some have theorized that they are akin to gods or massive demons in the Mario universe.

Other fan theories tie their presence to other Mario games. The HellValleySkyTrees bear a resemblance to the alien Shroobs, from Mario & Luigi: Partners in Time, which also have big eyes. Their bodies also resemble that of an unused boss from the first Luigi's Mansion called an "Elh." That being said, no official connections have ever been made.

RELATED: The Most Useful Partners in Paper Mario

There are some possible explanations that could make sense of these mysterious figures. According to YouTuber Geek Remix, there may be a benevolent side to these inactive figures. By dissecting the name, "Hell Valley" could reference the winter hot springs, Jigokudani, and the "Sky Trees" could be based on kind tree spirits known as Kodama. Nintendo is known for incorporating Japanese culture and mythology into its games, so this could be a subtle and well-hidden reference.

Of course, the strange file name could be just that -- a bizarre but descriptive name that has no alternate meaning behind it. "Hell" could simply refer to a hot area, like Shiverburn Galaxy with its lava. They are found in a valley in the sky, which would explain the next parts of the name, leaving these figures as nothing more than alien-looking trees. Regardless of what Nintendo intended for theHellValleySkyTree, though, the figures have spawned some creative explanations for their potential origin.

KEEP READING: Metal Gear Solid Has a Weird History With...Yoshi?