However, a rescued NPC will stay rescued, and respawn without needing to be found again. the 50 SC requirement for the Merchant), that has to be met again for the respawn. (Old-gen console and 3DS versions) If the NPC has an inventory or population requirement for their initial spawn (e.g. If an NPC is killed, they will respawn after a delay, as long as a suitable vacant house is still available.
Most NPCs are town NPCs, appearing after various milestones are achieved in game advancement. Some NPCs also have other options that perform other functions. They sell items to players in exchange for coins, and can be sold items by a player to obtain coins. Most NPCs are vendors, displaying a shop inventory when the " Shop" option is selected. Standing near an NPC and pressing the ⚷ Open / Activate button on them will open a dialogue window with one or more options for the player to select. NPCs are friendly automated non-player characters that provide services to players.
For a complete list of NPC names, see NPC names.