F!Gaster

× OVERVIEW ×

W. D. Gaster was the Royal Scientist before Alphys, and was stated to have irreplaceable brilliance. Gaster's Followers imply that she created the CORE and has disappeared. During normal gameplay, W. D. Gaster is typically unmentioned. Despite this, River Person, rare Fun Value events, and certain Inaccessible Rooms hint at her existence. This includes Room 264, named room_gaster.

In particular, Gaster's Followers relay Gaster's implied fate. One iteration says that she "fell into her creation," the second states that "her experiments went wrong," and the third claims she was "shattered across time and space." Similar to Sans and Papyrus, W. D. Gaster's dialogue uses a unique typeface, named Wingdings.

× PHYSICAL DESCRIPTION ×

The only in‑game visual tied to W. D. Gaster is the sprite often called the “Mystery Woman,” appearing in rare hidden events. There’s no consistent official artwork showing her fully, but fans associate her with a tall, thin figure in a tuxedo or dark suit—typically colorless or monochrome—inspired by the mystery moman sprite. According to internal descriptions, Gaster’s form is unstable—her appearance, height, and weight appear to shift because her fragmented existence across time and space prevents her from coalescing into a stable body. Fan art often visualizes Gaster as a skeletal humanoid with a skull-like face (sometimes resembling Sans or Papyrus), long limbs, sunken dark eyes, and wearing a formal black suit with tails—reflective of her eerie aura.

× PERSONALITY ×

Ingame, Gaster vanished after an accident involving her creation (likely the CORE). Her consciousness—or fragments of it—are rumored to be scattered across time and space, making her personality largely unknown and interpreted through fragmented NPC lines. The few lines from “Gaster Followers” indicate a quiet, almost spectral presence who may still observe events from afar. She's never seen speaking directly, and any voice or sound associated with her is cryptic, such as “Gaster’s Theme.” As the former Royal Scientist, Gaster was brilliant, having developed powerful technologies like the CORE. She's often imagined as deeply curious or obsessed, which may have led to her downfall.