In the Animal Crossing series, the mole who appears after an unsaved reset is Mr. Resetti.
Mr. Resetti is a short-tempered mole whose job is to remind players to save before quitting. In the earlier games, switching off the console or resetting without saving caused him to appear the next time the game was launched. He would deliver a lecture, often speaking directly to the player and breaking the fourth wall.
His stern behavior was designed around a practical game problem: players could reset repeatedly to manipulate events, shop inventories, or other random outcomes. Resetti’s long speeches discouraged that habit while turning a technical safeguard into a memorable character encounter. His full name is Sonny Resetti, and his brother is Don Resetti.
New Horizons changed his role because the game uses autosaving. Rather than appearing after every unsaved quit, Mr. Resetti operates the rescue service and later appears in other activities. A common mix-up is calling him simply “Resetti”; that is part of his name, but the canonical character name in English is Mr. Resetti.