Tom Nook
From Wild World Wiki
Tom Nook is a raccoon. His name comes from the japanese word for "raccoon", which is "Tanuki". This could also be classed as a reference to the Tanuki Suit in Super Mario Brothers 3, which enabled Mario, the main character, to become raccoon-like and fly though the air.
Tom Nook runs the local store, and is most likely the richest character in the entire game, with fingers in many pies. He is somewhat good-natured, and helps out your character by giving them a loan and a house. Whenever a loan is paid off, he expands your house, giving you a bigger loan. For a short while, he gives you a job in his store, but once you've finished your errands, he leaves you on your own. At this point, you are allowed to purchase merchandise and items from his store.
He expands his store as more money (and visitors) comes in, making it bigger each time. The four stages of Nook's Store develops as follows:
Family
Tom Nook has two younger nephews, Timmy and Tommy. When he expands his store to Nookingtons, the duo work on the upper floor, selling wallpaper, carpets, paint and furniture. While it may be questionable that Tom Nook uses child labour, the two of them seem to have no arguments, and even volunteer to repaint your house for you.
Rumours
It is rumoured by several villagers (such as Bones) that Tom Nook is not actually a raccoon, but instead a "guy in a raccoon suit", and that the zipper is "well hidden". It is unconfirmed (and unlikely) that this is true.