Mr. Resetti was created to discourage the use of the reset button.
If you don't know this peculiar guy, you're lucky. Perhaps one of the most annoying characters found on video games, Mr. Resetti lives up to his name. Any time you reset your console while playing Animal Crossing, you'll get a visit from this mole. He might seem cool, harmless, or even cute but if you piss him off, you’re in for an earful. If you think he isn't serious, you're wrong. He means business: reset just once, and he will burrow to your house, stop you at the door and lecture you on the morality of your actions. You will be completely unable to continue with the game until you satisfy him, or rather, until he satisfies himself. Eventually, he will even threaten you with resetting your game himself (although he never does). The only way to avoid Mr. Resetti is to just not reset. So if you're thinking that you can erase your misfortune, know that Mr. Resetti will be there to replace the consequences of your actions.
He is one of the most righteous characters in the Animal Crossing universe. He doesn't lack moral fiber: he is moral fiber. His job is to keep cheaters outside of the game, and he takes that job very (perhaps excessively) seriously. He refuses to give any player a free pass, with the exception of first-time offenders.
Mr. Resetti is shown through his lectures to have serious stress and anger issues. His head will pound and redden, his voice will raise, and the barely contained one-mole-apocalypse under his facade will quickly become obvious to most players. On occasion, he will discuss his home-life, talking about visits to the doctor, his favorite sock, his hygiene rituals, and supply you with anecdotes that usually fail to create the parallel he intends.
Despite all this, he seems to have good intentions towards the player. Mostly.
Resetti has a brother Don which is the polar opposite of him. You can meet Don if you use the reset button to much then he'll come over to your house and give you 100 bells to stop.
Super Smash Bros. Brawl
Mr. Resetti can also be found in Super Smash Bros. Brawl as a assist trophy and as a trophy. Sometimes can be found sipping coffee at the roast at a specific time.
In City Folk if you visit the city after 8:00 P.M, you'll find the Resetti Operation Center which he'll give you a silver shovel. In the region only American release release of Animal Crossing: City Folk, the player can receive a trophy featuring Mr. Resetti once talking to the Mayor Tortimer on Groundhog Day.