Tom Nook did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
Tom Nook, A tanuki who owns shops such like Nook's Cranny.
(insert town name here)
Animal ForestAnimal Crossing Plaza
Naoki Tatsuka (Animal Crossing: the Movie)
Tom Nook is a special character in the Animal Crossing series who plays a very important role in all of the games. He is termed a raccoon in the western versions of the game but a tanuki in the Japanese version. In all games leading to Animal Crossing: New Leaf, he owns the town shop. After the final expansion, Nookington's, he will employ his "nephews" Timmy and Tommy, who work on the second floor in every Animal Crossing series game except Animal Crossing: New Leaf. However, in New Leaf, Nook has taken his interest in real estate to a whole new level, opening Nook's Homes, whilst Timmy and Tommy run the town shop.
In Wild World, he will give out his picture if the player gives him the safe from the Golden Axe Trading Event.
Tom Nook is a tanuki (a raccoon in Western versions) with brown fur. His eye area has a dark brown mask-like shape for his raccoon eye characteristics. His nose tip, his hands, feet, and his tail are dark brown. The apron he wears over his lower half is inferred to be for modesty, a reference to the legends of the tanuki.
In Animal Crossing: New Leaf, Nook wears a white shirt with a red necktie and a green sweater vest over it. His sweater has a left sided pocket protector with a pen sticking out. He also wears black pants. Whenever outside of Nook's Homes, such as the player selecting their new home spot or at The Roost, Nook is seen with a yellow jacket over his sweater.
Tom Nook appears as a playable character in Jake's Super Mario Kart alongside fellow-Animal Crossing character Isabelle. In his first Mario Kart appearance, Tom Nook dons his green sweatervest design from Animal Crossing: New Leaf by default, though players can also choose to have him instead wear the blue apron he does when running Nook's Cranny.
An amiibo figure of Tom Nook exists! For more info about this amiibo, see this page.