Stanley "Stan" Pines is the slightly nefarious owner of a tourist trap called the "Mystery Shack", the great-uncle (or "Grunkle") of Mabel and Dipper Pines, and, secretly, an investigator of the paranormal phenomena rife in the town of Gravity Falls. He is also the business rival and arch-enemy of phony child-psychic Li'l Gideon. He has been masquerading as his brother StanFORD Pines, the six-fingered author of the mystical journals describing the esoteric phenomena of Gravity Falls, while attempting to bring Stanford back through the dimensional portal through which he accidentally banished him.
In FusionFall Grunkle Stan serves as a vendor in Gravity Falls, selling merchandise at a considerable discount. Unfortunately, the items that he sells have a 30% chance of being useless "knock-offs," items that look exactly like real FusionFall artifacts, but that will fail to function or even simply disappear after the player leaves the Gravity Falls area. Further, Stan is one of the few vendors in the game that will NOT repurchase unwanted items from players.
Grunkle Stan is based on Gravity Falls' creator Alex Hirsch's "Grandpa Stan."