Undertale does two things extremely well. The first is having many hidden details within the game. So many moments in this game are easy to miss, and finding these nuggets of information really adds to its replay value. The second thing Undertale does well is characters. Every main character is fleshed out and personable, and you get to see them at their worst and their best.
One character that is great is Undyne The Undying. Undyne is the head of the royal guard and tasked with eliminating any humans. She is a very passionate character who wants to be a hero above all else and, like many other characters within the game, is deeply nuanced and complex. It easy to miss some of the smaller details about her, but here some of the ones that we thought were interesting.
10 Undyne the Undine
Like all the residents in Undertale, Undyne is a monster. The monster is she is specifically is an Undine. These creatures are a water elemental, which have been depicted to be like water nymphs or mermaids. This is definitely fitting for Undyne who is clearly an aquatic, fish monster. The name Undyne is also a play on word of undying.
9 True Hero
An emotional and difficult moment within the game is when Undyne goes into her “Undyne The Undying” form during a genocide run. What makes this moment so powerful is how much a foil it is to the protagonist. A lot of the genocide run is about letting the player know they are a bad person, and Undyne going into her Undying form is essentially letting the player know they are not the hero anymore. Undyne is.
8 Obliviously Enjoys Anime
In order to better understand humans, Undyne went through a lot of research on them. However, most of this research is actually just her watching anime, which is a far cry of what humans actually are. A lot of comments she makes about humans are actually things she has seen humans do in shows like Bleach and Code Geass.
The funny thing about this research is that she does not even realize she is watching anime, and all the while makes fun of people for being nerds when she is one as well. However, it does make her romance with Alphys more fitting, as they end up sharing something in common.
7 Character Naming
While Frisk is the actual name of the protagonist, Undertale lets you name your character. However, some names are off limits with Undyne’s being one of them. When trying to name your character Undyne the response will be “Get your OWN name!” Undertale is no stranger to meta jokes, but this one has some personality in that it is clearly Undyne saying this to you.
6 Napstablook is scared of her
Napstablook is basically known for two things: making tight beats and being afraid of everything. Because of this, it should be no surprise that Napstablook is afraid of the intimidating Undyne. It is a little sad considering the two of them are neighbors, and Undyne seems to be actually caring and friendly towards Napstablook.
5 Can play piano
Undyne is not simply a warrior, but also a talented pianist. There are many subtle instances showing Undyne’s skill with the piano. For one she used to teach the character Shyren how to play piano, she has a piano in her house, and there is also heavy implication that the song you hear before entering Undyne’s house to befriend her is Undyne playing the piano. Further speculating, the song “Battle Against A True Hero” is heavily piano based and a theme song for Undyne, so this song may also be implied to be played by her.
4 Gerson
Before the climactic fight between the player and Undyne, the Monster Kid accompanies you and talks about how much they look up to Undyne. Funnily enough, Undyne used to look up the old merchant, Gerson. This turtle used to a famous hero in his prime days, and Undyne would follow him around. This would prove somewhat problematic for Gerson as Undyne would end up attacking people she thought were his enemies, but were actually just everyday people.
3 Dislike For Nerds, however...
Undyne is the sort of person that would best be classified as a jock. She is tough, passionate, and competitive, usually trying to prove herself to the people around her. Like any stereotypical jock, Undyne has it out for people who are nerds.
If the player interacts with her bedroom, Undyne will say that no nerds are allowed in there. However, right after she says this, she acknowledges that some nerds are allowed in. This is her saying that she has a soft spot for Alphys who, despite being a nerdy character, is someone she deeply loves.
2 Alphys Exceptionalism
In general, Undyne is a pretty adamant person who goes by certain rules. However, she does break those rules for the people she cares about. As acknowledged from the entry above, she clearly is letting the rules slide for her romantic interest, Alphys. Aside from letting nerdy Alphys hang out with her, Undyne also keeps soda around for Alphys despite hating the beverage herself. It is also implied that Alphys is the person who got Undyne into anime, which would probably not fly with Undyne if it was any other person.
1 Her House
A lot of the main characters in the game have houses that give indications to the kind of person they are, but Undyne’s seems to be one of the more obvious. Her house is a scaly, fishhead with an angry expression on its face. This is of course much like our favorite rage-fueled fish friend. Additionally, when the house catches on fire it has a frowning mouth expression, and the window eyes look sad and teary. If the player tries to knock on the door when the house is on fire, it says “Sounds like only fire lives here now.”