Character from Undertale / Deltarune by Toby Fox
An ancient turtle shopkeeper who fought in the Human-Monster War and now sells junk in Waterfall — the Underground's grumpy living history book.
Gerson is one of the oldest monsters alive, having fought in the Human-Monster War. He is the primary lore source in Undertale — he explains the Delta Rune prophecy, the War's history, and drops the detail that Toriel was 'really the brains behind the throne.' He is grumpy, knowledgeable, and completely unkillable on the Genocide route (the game won't let you fight shopkeepers). In Deltarune, he is deceased — his son runs the shop in his place. This is one of the details that confirms Deltarune is a different timeline, not a sequel.
An elderly turtle monster with a grizzled face and the bearing of someone who has lived far too long to be impressed by anything. He runs a small shop in Waterfall filled with miscellaneous items.
Also known as: Hammer of Justice