Character from Deltarune by Toby Fox
The man who speaks in hands. The voice at the start of the game. The figure in the darkness who may be pulling strings that even the player can't see.
Gaster is Deltarune's ghost in the machine. He created the game's intro sequence — the voice that asks you to create a vessel, then discards it because 'no one can choose who they are in this world.' He may be the Knight. He may be the mysterious caller. He may be the reason the game exists at all. In Undertale, he was the Royal Scientist before Alphys — he fell into his own creation and was scattered across time and space. In Deltarune, his presence is felt in every unexplained phenomenon: the egg man, the sound test room, the bunker door that won't open. Sans references 'a friend who speaks in hands.' Spamton's caller vanished without a trace. He is the deepest layer of Deltarune's mystery, and Toby Fox feeds the fandom exactly enough crumbs to sustain theories without ever confirming anything.
Never fully visible in Deltarune. In Undertale, he appeared as a cracked, melting face — black and white, skeletal, with holes in his palms. In Deltarune, he is the voice in the opening sequence, the presence behind the survey, and possibly the mysterious caller who contacted Jevil and Spamton. He exists in the margins of the game — in unused rooms, in garbled text, in things that shouldn't be there.
Also known as: Gaster, The Man Who Speaks In Hands, W.D. Gaster, Mystery Man