Inaccessible Rooms

Within Undertale, there are various rooms that cannot be accessed through conventional means. These rooms cannot be accessed by changing the save data, as they will immediately redirect the player to a black room with a white dog. However, they still are present in the game data, and can be accessed in other ways.

Rooms are listed from the smallest number to the greatest number.

Room 123
Room 123, also known as room_water_prebird, is a room that is between room_water_farm and room_water_shop. It is a thin stretch of land that is surrounded on two sides by water. The path is covered in tall grass, which covers up an NPC that you can talk to. The NPC is never seen, but remarks about how they love to catch bugs in their spare time. They express sorrow, as they can only catch the same bug due to the lack of bugs in the underground. They will ask the protagonist to do something about their "friend", who they describe as having a creepy smile. If spoken to again, they will ask where the protagonist's "friend" went.