Undertale - weaver presents: strange days (part 3)

Spoilers kinda? It's more of a secret but just to be safe:

By modifying the game files a bit you can find out some backstory about the previous royal scientist, the one that came before Alphys.

His name is "W.D. Gaster", most likely a reference to Wingdings and Aster, two fonts. He speaks in Wingdings in the few recordings of what can only be assumed are his words. Wingdings is composed of various signs like the ones Asgore is using here.

Basically he's implying there is/was a connection between Sans and Gaster, which is also a popular theory considering what we know about Sans, his room and his garage, as well as the fact they both have names referencing fonts.