Who is Gaster?

Gaster, the man who speaks in hands, was the royal scientist before Alphys in vanilla Undertale made the core to the underground, bit no one knows who he actually was, or what he looked like before he shattered in space and time.

There is a 2% chance that you find a door in the middle of a hallway with a cross symbol above the abyss, with a weird skeleton-like being in the middle. Some people speculate that it is Gaster bit in the game files and the character list the thing is called the mystery man. On the Fun scale of Undertale, Gaster has the highest attack and defence, way way way higher than undyne the undying who has 99 on both and Gaster with the most cursed number 666,666 on both

It could be related to Sans and Papyrus, in Glitchtale all three of them were together.

If anyone else knows anything else about Gaster, reply to the post and I will read it and edit this post.