Who is W.D. Gaster?
W.D. Gaster is Undertale's missing Royal Scientist, the one who held the job before Alphys. He built the Core in Hotland, the machine that turns geothermal energy into magical electricity for the Underground. Then he vanished, described in game as shattered across time and space.
He never appears in the main story and nobody discusses him directly. Players found him by digging through the game files.
Those files hold sprites known as Mystery Man, though the link between that sprite and Gaster has never been fully confirmed.
In game, the Gaster Followers give conflicting accounts of what happened to him. Sans's weapons are labeled Gaster Blasters in the files.
Toby Fox has kept all of it deliberately ambiguous. The Undertale wiki collects what players have pieced together.
Why does Gaster speak in Wingdings?
Undertale names its skeletons after typefaces, and each one speaks in the font he is named for. Sans talks in Comic Sans. Papyrus talks in Papyrus. W. D. Gaster talks in Wingdings, and fans read those initials as Wing Dings, with Gaster often taken as a nod to the Aster typeface.
The initials have never been confirmed. It is the fandom's reading, and a good one, but Toby Fox has not said so.
Wingdings itself has nothing to do with Undertale. Microsoft shipped it in 1992, and its actual history is stranger than the game's use of it.
Entry Number Seventeen
Entry Number Seventeen sits in a hidden room in the game files, presented as the missing log from a numbered series of lab entries. It is written in uppercase Wingdings, with no dialogue portrait and no speaker named, which is a large part of why it unsettles people.
The uppercase part matters. Run it through in lowercase and every symbol comes back wrong, which is how most bad Gaster translations happen.
We are not reprinting the decoded text here, since it is dialogue from a commercial game. Paste the symbols into the tool and read it yourself.
How to decode Gaster text yourself
- Copy the Gaster symbols from wherever you found them.
- Paste them into the first box above.
- Leave the case exactly as it appears in the source.
- Read the English in the second box.
One catch stops a lot of people here. If your Gaster text is a screenshot rather than copyable characters, there is nothing to paste.
You have to pull the symbols out of the image first.
If the output still reads like nonsense, the source may not be Wingdings 1 at all. Switch versions on the main tool to check.
Want the whole mapping? The full symbol table lists every key.
Gaster in Deltarune
Gaster has never actually appeared in Deltarune, Toby Fox's parallel game, but the allusions pile up. Typing his name during the intro restarts the game. Hidden Wingdings text describing the Prophecy sat on older versions of the Deltarune website. There are nods in the soundtrack too.
Chapter 5 arrived in June 2026 and Chapter 6 is targeted for 2027, so this section is a moving picture.
Plenty of fans read the Voice as Gaster. That is interpretation rather than confirmation, and the difference is worth keeping straight.
Check the Deltarune wiki for anything that has landed since.
Gaster translator FAQ
Is Gaster's language the same as Wingdings?
Gaster's language is exactly the same as Wingdings. There is no separate cipher and no custom alphabet, so his dialogue decodes with any standard Wingdings mapping. Undertale draws the glyphs as pixel art, which is why they look different from the font on your computer.
What does W. D. stand for?
W. D. is widely read by fans as Wing Dings, matching Sans and Papyrus being named for their own fonts. Toby Fox has never confirmed it in game or out, so treat it as the fandom's best reading rather than settled fact.
Can you meet Gaster in Undertale?
You cannot meet Gaster in normal play. He surfaces through the Gaster Followers, grey NPCs that appear under specific conditions, and through sprites left in the game files. Naming the fallen human Gaster restarts the game instantly, which is how many players first hear about him.
Why is my Gaster translation coming out wrong?
Your Gaster translation is probably coming out wrong because of letter case. Wingdings gives uppercase and lowercase completely different symbols, and Entry Number Seventeen is written in capitals, so set the tool to uppercase before you translate anything from it.
Is Gaster in Deltarune?
Gaster is alluded to in Deltarune but has never been confirmed to appear. Typing his name during the intro restarts the game, hidden Wingdings text sat on the old website, and many fans read the Voice as him. None of that is official.