The ghost had pale blue skin, frizzled gray hair, and a large mouth with sharp, red teeth. He wore a chef's uniform consisting of a light gray coat along with a white hat and bib, all tattered. His pants were dark gray and he had tiny legs and feet, much like Mr. Gordon himself. Unlike the real Chef Pierre, the ghost lacked a mustache.
He was malevolent and menacing, claiming that he would take everything. He had a French accent and often said "Sacre boo!"
When he was alive, Pierre Goulash was a chef employed by Daphne Blake's great-grandfather. They got into a heated argument which resulted in Pierre being fired. He swore he would come back and take everything from the Blake family.
A Pup Named Scooby-Doo
The ghost's first act was to rob everything from Daphne's room, leaving it completely empty. This prompted the gang to investigate. Mr. Gordon loaned them Robopup so that he could supposedly help them solve the mystery.
Shaggy Rogers and Scooby-Doo first encountered the ghost while checking out the Blakes' pantry (which was more like a grocery store). He chased them around in circles until he eventually started throwing food at them, which of course, they had no issue with. Scooby tossed a watermelon in his face and the two got away from the ghost.
Shaggy and Scooby told the rest of the gang about the ghost chef, and they decided to ask Daphne's parents about it. Though they didn't believe in ghosts, they told them about Chef Pierre and why he'd want to steal from the Blakes. Just then, the ghost showed up, scaring them all. Scooby panicked and tried to climb up a curtain, which caused the curtain to fall on the ghost, giving everyone time to escape.
Later, the gang found the stuff stolen from Daphne's room in the Blakes' subway station. However, they were confronted by the ghost again. He chased them all over the place until they lost him in the gardener's shack, where Velma Dinkley came up with a plan to capture the ghost.
While the ghost was busy loading Daphne's stuff onto the train in the subway station, Scooby popped out of a drawer and lured the ghost onto the bed, where the kids pulled a sheet down on the ghost and restrained him. He was unmasked as Mr. Gordon, who wanted to steal from the Blakes so he could get rich. He was secretly assisted by Robopup, who was supposed to be solving the crime but was actually throwing everyone off the trail. 
Ghost: Sacre boo! I will take everything!