The character with the "creepy smile" is possibly the Mystery Man seen in Room 269 which may be Gaster, and the evidence supporting this theory lies within the word "smile" in the dialogue, as the track that plays in Entry Number Seventeen is named mus_smile.

Mar 19, 2023 · It contains "Gaster's theme" which is a simple creepy melody, that refuses to stop playing when you start it. If your fun value is 66, you have a 10% chance to find a hidden door in waterfall. If you go through it, you can see the commonly assumed appearance of Gaster.

Feb 9, 2016 · TL;DR: Gaster serves as a parody on cut content, and how horrifying it is to live on as a cut character, and be aware of everything at once. W.D. Gaster, like almost ALL things in Undertale, is a deconstruction.

Nov 9, 2022 · Doctor WD Gaster was the royal scientist before Alphys. He supposedly made the Core. One day, his experimentS went wrong and he “died”, being shattered across time and space.

Apr 24, 2021 · While a literal Satanic character doesn't seem right with Undertale's themes of forgiveness and hope, there is definitely something super creepy about the Gaster mystery that fits with this theory. If the player has specific Fun Values, they have a chance to encounter four of Gaster's followers, among other secrets in places like Hotland.

The character with the "creepy smile" is possibly the Mystery Man seen in Room 269 which may be Gaster. However, it can also be Flowey (who follows the protagonist throughout the game), Sans, or even the fallen human .

Oct 31, 2024 · W.D. Gaster is a cryptid who is namedropped in Undertale 's easter egg events and appears more properly in Deltarune.

May 2, 2021 · But Gaster simultaneously hooks the dedicated player into an unfinishable puzzle. The Gaster mystery is the kind of thing you have to seal away in a glass box, or else it doesn’t work. It’s a mystery you can’t treat as a mystery.

Aug 8, 2022 · The mystery surrounding him, his looks, his voice in the Entry number 17, everything about him gives me the spinechills. ESPECIALLY the sounds in…

Found in one of the game's unused rooms that can be accessed after removing the Dog Check, this character, known as "Redacted" within the game's files, is a mysterious, ghostlike figure with a generally unfinished appearance. Some fans believe this to be the true appearance of Gaster as opposed to the Mystery Man, evidence of such goes as follows: