Undyne's house

Huff... puff...!
YEAH!!! That's MY HOUSE!!!

Undyne, upon calling Papyrus immediately after befriending her

Undyne's house is the home of Undyne that appears in the Waterfall area. It is a key location in the True Pacifist Route.

Undyne's house is situated next to Napstablook's, which Undyne notes when calling here in front of it.

Features

• The hangout with Undyne occurs here if the protagonist gained no EXP. After the hangout, the house is no longer accessible.
• If Undyne is befriended after completing the Neutral Route and backtracking (or after resetting and defeating Mettaton), Undyne's Letter can be obtained here instead of in Snowdin.

Main story

Neutral Route

Undyne's house does not yield anything of importance until Papyrus calls the protagonist in front of the "WELCOME TO HOTLAND!" sign while being pursued by Undyne to say that he, Undyne, and the protagonist should all hang out sometime and then says to meet at her house later. Returning to this location after the call causes Papyrus to show up in front of her house. Backtracking to this area immediately following the phone call before Undyne passes out in Hotland results in special dialogue.

Befriending Undyne can be completed on the Neutral Route, but it is an integral part of the True Pacifist Route. The requirements for this event is that the protagonist must not kill anyone before starting this event or else Undyne refuses to open the door and become friends with a murderer. The protagonist must also give Undyne water when she passes out in Hotland, or else she gets heat stroke and is unable to open the door.

True Pacifist Route

If the protagonist did not befriend Undyne before defeating Asgore and backtracks to befriend her, she gives Undyne's Letter immediately after the event. Undyne mentions that Papyrus proposed the idea of giving the letter to the protagonist, but he told her about it when she still hated them. If the protagonist's inventory is full when Undyne attempts to give them the letter, the letter must be obtained from Papyrus and Sans's house.

Sublocations

Exterior

Undyne's house appears to be a massive angry fish with the door resembling the mouth and the windows resembling the eyes. After completing the events that occur in this area, the house turns entirely black, and fire can be seen from the house's windows and slightly open door. The "eyes" also change from angry to teary. Mad Dummy appears here after their battle, unless killed during the Genocide Route. At the end of the True Pacifist Route, Mad Mew Mew replaces Mad Dummy on the Nintendo Switch version of Undertale if she was fought.

Knocking on the door of the house at certain points in the game can result in varied dialogue:

• Knocking on the door after fighting Undyne but not giving her water: "You hear irritated groans from the inside."
• Knocking on the door after fighting Undyne and giving her water but before hanging out with Papyrus: "It doesn't seem like anyone is home."
• Knocking on the door after killing Undyne: "It doesn't seem like anyone is home. And you get the feeling no one will be."
• Knocking on the door while the house is burning after befriending Undyne: "Sounds like only fire lives here now."
• Knocking on the door if Papyrus is in front of it: "If someone's there, they aren't answering the door."
  • If all conditions to start the hangout are met, the door cannot be knocked.

Interior

The interior of Undyne's house

The interior of the house consists of a kitchen with a table, a chair, a fridge that keeps food warm, a sword, a piano, and a window on the left side of the house. The only other door in this room that is not the entrance is the locked door that leads to Undyne's room.

Trivia

Concept art for Undyne's house

• Papyrus's small animation where he dances or walks in place before he enters Undyne's house is supposed to represent him wiping his feet on the mat in front of the house.
• During the hangout with Undyne, the second-from-the-top tea box is transparent. It changes to green after being knocked off the counter.