

None of this is directly confirmed, though it certainly is possible. A popular theory is that Gaster was their father, especially given the strange blueprints players can find in Sans' shed near the end of the game. For example, given that he's likely named after the typeface he speaks in, many speculate that he's somehow related to Papyrus and Sans. There's also a fair amount of speculation on Gaster's relationship with other Undertale characters. The CORE was one such experiment that would prove successful, though Gaster would fall into it and be shattered across Undertale's possible multiverse, hence why he only appears within the game's files. Gaster (possibly "Wingdings" Gaster after the font) was the royal scientist who performed experiments to create a power source for the Underground. With all of this secret content, Undertale fans have pieced together some significant information. RELATED: Audio-Based Indie Game The Vale Broadens Representation & Accessibility This entry is written entirely in Wingdings and talks about an experiment that the writer thinks will be "very very interesting" while also describing something as being "darker, darker, yet darker." This room is called "room_gaster" in the game files. The room where this dialogue plays can't actually be found without modifying the game files with a save editor, though it's still an important bit of lore that helps players understand who Gaster is.

The last major piece of information about Gaster can be found in a secret True Lab entry.
