- Requirements: The protagonist has killed Toriel but has not killed Undyne.
Undyne becomes the ruler of the Underground and enforces a policy to destroy all humans who enter. She plans to wage war on humanity, has militarized the Underground, and personally plans to destroy the protagonist. Sans mentions not being able to reach Toriel and, if Papyrus is dead, implies that she has been killed and that the protagonist is responsible. If Papyrus is alive, however, he simply says she might not be feeling well, and allows Papyrus to take over. If Papyrus has been killed, Sans warns the protagonist to watch themself as “things are looking real bad for you.”
However, if Papyrus is alive and befriended, Papyrus interrupts the call and tell the protagonist that Undyne has appointed Papyrus to “The Most Important Royal Position,” which is a figurehead position where he stands around and looks cute, but he is proud of it. Papyrus says that the protagonist should come and visit, though he also says that Undyne will probably kill them if they do, but says that they should risk it.
Whether or not they kill Mettaton has no effect on the dialogue of this ending.
5. Mettaton Ending
- Requirements: The protagonist has killed Toriel and Undyne, but has not killed Mettaton.
Mettaton becomes ruler of the Underground since Undyne disappeared, and establishes a dystopian society in which he brainwashes the entire Underground with his television show. Sans mentions that he became his agent and then hands over the phone to Mettaton.
Mettaton establishes a policy on humanity that any human that falls can join his fan club for free. He says that he has created a statue of Alphys, but then goes on to say that he was “not the greatest to her.” He says that he was going to apologize to Alphys and ask her to help him rule, but could not find her, and emphasizes “TRUST ME. I LOOKED.” Mettaton then asks the protagonist to think of him always and ends the phone call there.
If Papyrus is alive and befriended, he then joins the call to mention that he has become Mettaton’s second agent. He says that things have gotten a lot better since the protagonist came (excluding the fact that everything is sad and anyone who does not worship Mettaton goes missing), but misses Undyne and asks the protagonist to say “hi” if they see her.
- Requirements: The protagonist has killed Toriel, Undyne, and Mettaton, but has not killed Papyrus.
By process of elimination, Papyrus became the ruler of the Underground, though Sans does most of the work. Sans tells Papyrus that Asgore, Alphys, Mettaton, and Undyne are on vacation. The Underground is improving; productivity is up, and Papyrus cooks everyone spaghetti. The human policy instituted is that humans cannot be judged to be all good or all bad. Either way, they get puzzles. Once Sans leaves, Papyrus expresses distress on his new responsibility as the ruler when people “WANT TO GIVE UP” and how he misses all his friends; he mentions how “Undyne never picks up his calls,” and that “they must be really enjoying themselves.” However, Papyrus reassures the protagonist that he is determined to “MAKE EVERYONE GIVE UP GIVING UP“, and hopes to get out of the Underground and hang out with the protagonist again.
- Requirements: The protagonist has only killed Toriel, Papyrus, Undyne, and Mettaton. No other monsters have been killed, Glyde and So Sorry included.
A small, white dog becomes the president of the Underground. The dog sleeps on the throne and does absolutely nothing. Strangely, this is the best life for everyone. Oddly enough, Sans does not mention the protagonist killing Papyrus in this phone call. “Dogsong” plays during the call just like in the Impossible Ending.
- Requirements: The protagonist followed the Genocide Route requirements throughout Waterfall but aborted the route during the travel through Hotland.
The protagonist does not encounter Alphys during this route, as it requires killing Undyne the Undying, which preempts the protagonist’s meeting with Alphys in Hotland. After Sans finds the protagonist’s contact information, he hands the phone over to Alphys, who has now become the new ruler of the Underground.
Alphys explains that after hearing Undyne’s last words, her resolve was strengthened, and she proceeded to evacuate the remaining monsters in the Underground to a safe location (presumably the True Lab). The survivors lauded her as a hero and elected her as the new ruler. Despite her confidence in her governing abilities, she remains anxious around people. After mourning the loss of her friends, she ends the call saying that she should have killed the protagonist when she had the chance.
9.Flowey’s Parting Words
After the phone call, if the protagonist had spared Flowey, he appears to talk to the protagonist. His dialogue depends on the protagonist’s actions during the neutral route.
- If the protagonist had killed some monsters, Flowey wonders if killing is necessary and asks the protagonist if they can reach the ending again without killing, and he will not kill Asgore, and maybe the protagonist will have their “happy ending.” Flowey remarks that he intends on watching before leaving.
- If the player reloads their SAVE and triggers the neutral ending a second time, Flowey assumes the protagonist wants to be friends with him. He proceeds to insult the protagonist, saying that he only cares about one person but ultimately truly does not care about them.
- If the player reloads their game and triggers the neutral ending a third time, Flowey asks if the protagonist wants to start the Flowey Fan Club. He then tells the protagonist to talk to Papyrus about it, as he started one multiple times. Flowey goes on to say that Papyrus was one of the better characters to mess around with and took a long time to get bored of him.
- If the player reloads their game and triggers the neutral ending a fourth time, Flowey jokes about the Flowey Fan Club. Flowey then warns the protagonist not to let Sans know anything about them, as he caused Flowey’s fair share of resets.
- If the player reloads their game and triggers the neutral ending a fifth time, Flowey notes that the protagonist is simply bored and just want to see what Flowey has to say. He then refuses to talk to the protagonist any further.
- If the player reloads their game and triggers the neutral ending a sixth time and onwards, Flowey simply asks if the protagonist has anything better to do.
- If the player resets their game and reaches the neutral ending again without kills, Flowey notes that the ending is still the same and tells the protagonist that their choices do not seem to matter. He then tells the protagonist how to achieve a real happy ending: befriend Papyrus, Undyne, and Alphys.
- If the player resets their game and reaches the neutral ending again with kills, Flowey agrees that killing is fine, but proceeds to scold the protagonist for only going halfway.
- If the protagonist resets their game, reaches Asgore without kills, then kills Asgore at the end of the fight, Flowey scolds the protagonist that they are trolling themself because all they had to do was befriend Papyrus, Undyne, and Alphys.
- If the protagonist killed no one, Flowey wonders why the protagonist let him go and why they are being so nice despite leaving the monsters still in despair. He then tells them a way to get a better ending by befriending Papyrus, Undyne, and/or Alphys.
- If the protagonist befriended all the key characters without exploring the True Lab, Flowey tells the protagonist to see Alphys, as their date has just begun.
- If the protagonist aborts the Genocide Route, Flowey complains that they were so close to real victory, but the protagonist screwed it up. He begins to wonder if they wanted revenge against him but quickly insinuates that they wanted to see the monsters happiness before tearing it away. He then says that he will be “waiting for you.”