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Dr. W.D. Gaster

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Dr. W.D. Gaster
Type Ghost
Developer(s) Zarla
Origin Undertale (Handplates)
Language(s) English, Español, Français, 中文, Česky
Translator(s) doveofthedawn1), Sparrowho & Nynsanity2)
Sakura W.D. Gaster
Release date November 26th, 2017
Download (Español)3)
Download (Français)
Download (中文)

Spoiler warnings: ghost contains spoilers for Undertale.

Dr. W.D. Gaster is an aloof, mysterious old man skeleton with many dark secrets from the Undertale AU Handplates. He was released on November 25th, 2017.

Gaster focuses mainly on interacting with him via his menus, where the user can ask him questions, give him things, or use different actions. His dialogue varies wildly depending on what you've done or said to him, and he has many, many unlockable features, paths, and secrets. He tends to be distant and standoff-ish, but with effort the user can get in his good graces.

Gaster's dialogue contains spoilers for Undertale, so be warned. Many of his features, paths, and modes have been documented on youtube by Emilyerised.


  • Dialogue that changes dynamically depending on what the user has done or said to him.
  • A relationship system keeping track of how the user treats him, with different story routes for treating him well or poorly.
  • Items the user can give to him, some of them permanent and some of them temporary. Many have unique actions, poses, or interactions.
  • Many unlockable story events that add more dialogue and interactions, or even entire different modes.
  • An April Fools mode and a Halloween mode.
  • An ACT menu where the user can do various actions to Gaster that changes dynamically depending on what the user is doing. If the user is cruel to him, an option may appear to apologize for example.
  • If enabled, he can see what windows on the user's computer are open and comment on what the user has running. If they have VLC open, he might comment on them watching videos for example.
  • A back-up save option.
  • A question menu with enormous amounts of text, with each question having many possible answers that change depending on the user's relationship with him.
  • Gaster can speak directly to other ghosts, and has a fair amount of dialogue with Ghost Jam Temmie. He will also notice if other ghosts are also open at the same time as him and will comment on their presence.
  • Gaster can be reset, although certain actions carry over from one run to the next.
  • He has a changelog that pops up after he updates that the user can check for information.


Gaster is initially distant and suspicious of the user's intentions and he will often ignore or brush off the user's attempts to interact with him. He will refuse almost all items or physical contact unless the user builds some familiarity with him first. To begin to thaw Gaster's coldness, the user can…

  • Ask him questions about his life and his work. He has multiple responses to every question, usually at least 4-5, so it's worthwhile to keep pestering him about certain topics.
  • Give him cigarettes or coffee, help him with hiccups, or give him puzzles.

Eventually, Gaster will allow the user to touch him if they want, and will open up more when asked questions. He will also accept more items once he trusts the user more.

Even if the user has been treating him well, Gaster may still at times be arrogant, self-absorbed, secretive, brusque or sarcastic. It's just how he is.

Negative route

Alternately, the user can mistreat Gaster if they prefer. The easiest way to do this is to hit him, which has instant and noticable effects on all the user's interactions with him. Hitting him will lock off several different dialogue paths permanently for that run. Otherwise, the user can do other irritating things to bother him, such as nitpicking him or slapping cigarettes out of his hand. The more the user annoys him, the more options will appear for annoying him further. Actual violence is required for the most negative path, however.

As the user keeps hitting him, the punches will get stronger and harder. With enough punches, Gaster will become fearful and nervous when talked to or asked to do something, while the user will become more demanding. Further punches will send him into panic attacks, and a combination of punches and a certain ACT option will break him and send him into an unresponsive state, at which point the only option is to reset.

If the user builds their relationship up with Gaster very high, then hits him, it's considered a unique kind of betrayal and leads to different dialogue for most of his menu options.

Alternate modes


If Gaster is comfortable enough with the user and hasn't drank any coffee, there is a chance he may fall asleep randomly. He will stay asleep until he has a nightmare or the user wakes him up.

If the user is at the point where Gaster will allow them to touch him, they can nudge Gaster down to sit and put a blanket on him while he sleeps.

Pastel Gaster

Pastel Gaster appears on April Fools, and all the dialogue in the ghost changes with his presence. Several different functions and routes are also cut off while he's there. He'll disappear when April Fools is over.


Panicking Gaster appears during a story event. In this state he will do very little but hyperventilate, although he will still do most ghost functions properly. He just won't be paying very much attention.

The brothers

Most of the story progression for Gaster involves the brothers.

Finding out about them

Gaster won't talk about the brothers initially and will feign ignorance when asked. There are two different ways to discover them depending on what route the user is on.


This section contains spoilers for unlockable content.


This section contains spoilers for unlockable content.

Seeing them in person

Once the above has been accomplished, the user can unlock the ability to speak and interact with the brothers directly. This unlocks mostly the same between both routes.

This section contains spoilers for unlockable content.


This section contains spoilers for unlockable content.

The whole skelefamily

Once the user has seen the brothers in-person, there is a way to unlock all of them appearing together. This is currently not available if the user has hit Gaster into a fearful state. They have entirely new dialogue for almost all functions when together, while some functions are closed off.

This section contains spoilers for unlockable content.


Gaster makes use of the Z - Undertale balloon, a simple Undertale themed balloon.

Listed as “alt translation” on Gaster's download page. The original Spanish version is no longer available.