From the Super Mario Wiki
“Where'd you learn to cook, truck driving school?”
Gourmet Guy is an always-hungry Fat Guy who works for Bowser and appeared in the game Paper Mario. He can be easily bribed by giving him a delicious Cake. He says he doesn't know why people call him Gourmet Guy, saying he's just an ordinary food-loving Shy Guy. Despite being one of Bowser's henchmen, he actually helps Mario and Princess Peach.
First seen in Shy Guy's Toy Box during the events of Chapter 4, Gourmet Guy won't let Mario pass the path unless he has gives him a Cake. Tayce T. will cook one up for Mario for free when he returns her Frying Pan. When Mario gives the Cake to Gourmet Guy, he is so stunned by its taste, he starts flying around area like a rocket. He finally jumps off the screen, dropping a Cookbook that Mario can obtain to give to Tayce T., that allows her to make additional recipes.
He later appears in Princess Peach's Castle after Mario defeats General Guy and his Shy Guys. When Princess Peach enters the room, she sees Gourmet Guy. When he sees her, he first thinks that he should report the event to Bowser that Peach had escaped her room. But, deciding he was rather hungry instead, he decides to keep the event under wraps if Peach will bake him a cake. Since Peach did not have any ingredients ready to cook, Gourmet Guy lets her borrow the Castle Key to the kitchen so she can bake him a Cake. After Peach obtains the Castle Key from Gourmet Guy, he warned to her that there were guards on the first floor, and she must be careful.
When Peach and Twink come back to the room with the cake, they give it to Gourmet Guy. When he eats the Cake, he starts going wild; rushing by the area on the screen in the same manner as happened with the cake Mario gave him. When Gourmet Guy is done with the sugar rush, he tells Peach and Twink that one of the Star Spirits, Misstar, is currently inside at Mt. Lavalava on Lavalava Island. He also tells Peach and Twink that there is a Lava Piranha guarding the Star Spirit. He recommends that Twink tell the information to Mario. Leaving, he also briefly mentioned that he really doesn't dislike Mario.
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