W. D. Gaster

--- W. D. Gaster is one of Undertale’s greatest mysteries. Officially, he was the Royal Scientist before Alphys, credited with creating the CORE. But his fate is only told in whispers: “One day, he fell into his creation. His experiments went wrong. He was shattered across time and space.” He never appears in the main story, only through hidden rooms, cryptic sprites (like the “Mystery Man”), and dialogue from strange gray NPCs called Gaster’s Followers. These fragments suggest he exists in pieces, scattered across dimensions, remembered by almost no one. His text is written in Wingdings, and the initials “W.D.” are widely read as “WingDings,” paralleling Sans and Papyrus’ font-based names. Gaster is tied to the game’s meta-mechanics: unused music labeled “Gaster’s Theme,” the infamous Entry Number 17 log with its chilling “Dark, darker, yet darker” text, and Sans’ attacks named Gaster Blasters. These links fuel theories that Sans and Papyrus are his creations or successors, inheriting fragments of his knowledge. In Deltarune, hidden files and cryptic website teasers strongly imply his involvement, hinting he may connect both games. Yet his true nature remains uncertain: scientist, ghost, glitch, or guiding hand. More than a character, Gaster embodies absence and mystery — a being erased from existence, haunting the edges of the code, watching from the dark where players aren’t supposed to look.