- For the track named after this character, see Alphys (Soundtrack).
Dr. Alphys (/ˈælfiːz, -fᵻs/ AL-feez, AL-fis) is a female, reptilian monster that lives in the lab in western Hotland. She is the incumbent Royal Scientist, a position she was awarded by Asgore after the death of her predecessor. Asgore hired Alphys because she told him that she had created a SOUL; in reality, she created a robotic body for a ghost.
Alphys is a yellow, reptilian monster of similar height to the protagonist. She has scales, round glasses, protruding teeth (which seem to vary between two and three depending which way she faces), and normally wears a white lab coat. However, she wears a polka dot dress on her date with the protagonist.
Alphys is filled with guilt and insecurities about herself and her accomplishments. After she accidentally created the Amalgamates while experimenting with determination, she told nobody and became depressed.
Before the events of Undertale, Undyne met Alphys in the Garbage Dump, where Alphys was deep in thought. Alphys accidentally created the Amalgamates through experiments with Determination sometime before the protagonist falls into the Underground.
Alphys initially meets the protagonist in her lab. She explains that she has watched the protagonist throughout their journey using hidden cameras and adds that she wants to help guide the protagonist through Hotland.
Alphys explains that a robot she created, Mettaton, wants to kill the protagonist. Mettaton then bursts the wall and forces the protagonist into a quiz show; Alphys helps the protagonist by signing the letter of the correct answer with her hands. Mettaton catches on after Alphys excitedly answers a question about her favorite video game, and Mettaton embarrasses Alphys by asking the protagonist who they think Alphys has a crush on.
After Mettaton's quiz finishes and he flies away, Alphys offers her phone number to the protagonist. She notices that their cell phone is old and quickly upgrades it with features including texting, a key chain, links to two dimensional boxes, and access to the UnderNet. Alphys explains these upgrades and rushes into her lab's "bathroom."
As the protagonist progresses through Hotland, Alphys frequently updates her UnderNet status. She calls to help the protagonist with puzzles but dislikes to give them the solutions outright. Alphys stops posting status updates when she realizes that the protagonist has been reading them the whole time.
Mettaton antagonizes the protagonist in several deathtraps, but Alphys informs the protagonist of a phone upgrade to aid them in every situation. If the protagonist fails any of Mettaton's challenges, Alphys blames herself, and Mettaton helps her out by letting the protagonist go. Alternatively, Alphys takes some credit if the protagonist succeeds.
Alphys attempts to guide the protagonist through the CORE but struggles doing so because of the CORE's ever-changing layout. If the protagonist follows her instructions, they often encounter hostile monsters. If the protagonist does not follow her directions, she worries about their trust in her.
At the end of the CORE, Mettaton reveals that Alphys inserted herself into the protagonist's journey by creating obstacles for them to overcome together. While she is locked outside, Alphys instructs the protagonist to turn Mettaton around and flip his switch, making him vulnerable. After the fight, Alphys unlocks the door and looks at Mettaton's body. If the protagonist spared Mettaton, Alphys is relieved that he just ran out of battery power. If the protagonist killed Mettaton, Alphys pauses and slowly reassures them not to worry. She stays with Mettaton's body as the protagonist progresses into the next room.
Alphys catches up with the protagonist before they take the elevator to New Home. She admits that she lied to the protagonist, and that the protagonist will have to kill Asgore to pass through the barrier. She then leaves.
After the protagonist delivers Undyne's Letter to Alphys, Alphys reluctantly goes on a date with the protagonist because she thinks that they wrote the letter. She changes into a dress and takes the protagonist to the Garbage Dump for their date.
While there, the protagonist and Alphys roleplay to help Alphys open up to Undyne about her feelings. Undyne overhears them talking about her and approaches. Alphys confesses that she was trying to impress Undyne by making her hobbies sound more scientific, and Papyrus takes Alphys out for a lesson in self-confidence. Their training ends early and he sends her home.
When the protagonist returns to the lab, a note from Alphys lays on the ground in front of the "bathroom." The note directs the protagonist to the True Lab's entrance to discover the truth, in case they do not hear from her again.
The protagonist learns about Alphys's Determination experiments in the True Lab via consoles on the walls that have her lab entries on them. She isolated determination from the six human SOULs and injected it into monsters who had "fallen down" in an attempt to extend the longevity of their SOULs after death. None of the monsters died, and they were well for a short time before they melted together.
Alphys's lab entries explain that monsters lack the physicality that humans have, and that this is why the monsters fused together; their bodies could not handle high concentrations of determination. She did not tell anyone about the Amalgamates and feared hurting everyone's feelings.
As the protagonist reaches the power generator, Amalgamates approach and trap them. Alphys stops the Amalgamates and explains that they were "sassy" because they were hungry. Alphys then tells the protagonist that she had a change of heart and will tell everyone about her failed experimentation.
She then leaves the lab and returns the Amalgamates to their families.
Alphys also joins Undyne in breaking up the fight between Asgore and the protagonist. Alphys is surprised to see two boss monsters, and comforts Asgore after Toriel rejects his bid of friendship. Mettaton prompts the two to kiss, but Toriel interrupts them from doing so.
Alphys questions how Papyrus knew to call everyone to New Home, and appears alarmed when Papyrus informs her that "A TINY FLOWER HELPED ME."
After Alphys regains consciousness, she remembers little about what happened. She tells Asgore and Toriel about her failed experimentation; Toriel fires her.
After the protagonist wakes up, she discusses her plans to watch anime when they leave for the Surface. She also helps explain what anime is to Asgore, and asks for Frisk's help in doing so. Alphys tries to show Asgore anime on her phone but accidentally shows him a picture of robots kissing.
On the Surface, Alphys joins Undyne, who leaves to check on Papyrus. In the True Pacifist Ending Credits, Alphys relaxes on the beach with Undyne, Lesser Dog, Greater Dog, the Nice Cream Guy, and Onionsan. Undyne kisses her on the cheek, and she faints.
Alphys disappears in Neutral Route endings where the protagonist killed either Mettaton or Undyne; it is hinted that she may have committed suicide.
Alphys has a crush on Undyne, but Alphys fears Undyne finding out the truth if she confesses her feelings. Alphys tries to impress Undyne because she does not want Undyne to think that she is a nerdy loser. She also names variables after Undyne, writes her name in the margins of her notes, and writes fictions about them sharing a domestic life.
Alphys shares her love of human anime and manga with Undyne, though Alphys convinces Undyne that anime and manga are actual depictions of human history.
On a True Pacifist Route, Alphys and Undyne begin dating, and, in the True Pacifist Ending Credits, Alphys faints after Undyne kisses her on the cheek.
Alphys admires and supports the protagonist as they adventure through the Underground. She watches them via hidden cameras from the moment they leave the Ruins. She attempts to insert herself into the protagonist's journey by creating obstacles in Hotland, but she later admits that this was just an attempt to make herself feel better.
She dates the protagonist because she believes that the protagonist wrote Undyne's love letter; Alphys later admits that she has no interest in actually dating the protagonist and was only pretending to go on a date to be nice.
If the protagonist aborts a Genocide Route in Hotland, however, Alphys holds no positive feelings for the protagonist and says that she should have killed them when she had the chance.
Alphys works for Asgore as the Royal Scientist. She lies to Asgore about creating a SOUL and presents Mettaton as proof of her achievement in an attempt to impress Asgore.
She tries to do what Asgore asks of her, which leads to the failure of the determination experiments.
Alphys has a crush on Asgore and sometimes refers to him as "Mr. Dreamy." In the epilogue, Alphys comments that she has moved on from Asgore, and adds that she thinks Asgore and Toriel are a cute couple.
Alphys did not know about Toriel until Alphys met her while interrupting Asgore's fight with the protagonist. Even though Toriel fires her as Royal Scientist, Alphys easily befriends Toriel. Alphys also finds her attractive.
When Toriel questions how anyone could flirt with her, Alphys laughs hysterically. This is a likely reference to the positive fan reception of Toriel after the demo. Alphys also expresses her love of the "Tori and Gorey" ship, adding that she may write a lot of fanfiction about it.
Alphys used to live on their street. She was like a big sister to them and took them on trips to the Garbage Dump to find cool junk. They reveal that Alphys made Mettaton to impress Asgore, and add that no one has seen Alphys recently.
Alphys evacuates Bratty and Catty on a Genocide Route.
- Alphys is an anagram of "shy pal"; this could be where her name came from.
- It is also possible that Alphys's name was derived from the word "alpha," or the dominant leader of a group. This could allude to her role as the Royal Scientist.
- There is one instance where Undyne uses the possessive case of Alphys, possibly using the nickname "Alphy."
- When attempting to name the Fallen Human "Alphys," the response becomes "D-Don't do that." and prevents the name from being used. However, naming the fallen human "Alphy" gives a confused "....OK????" and is allowed.
- Alphys may know Sans; dialogue in the epilogue hints at this.
- Alphys's favorite anime, "Mew Mew: Kissy Cutie," may be a reference to Tokyo Mew Mew (also known as Mew Mew Power in North America), a typical romance magical girl anime.
- Posters in Alphys's lab share design characteristics with Mew Mew Power.
- Before the protagonist enters the True Lab, there is a note in the trash can that reads "I KNOW WHAT YOU DID." Flowey may have written this note to push Alphys to reveal her secrets.
- Alphys is the only major monster in the game who the protagonist cannot fight and, therefore, kill.
- Alphys's full combat capabilities are unknown. In the True Pacifist Route, she generates a wall of electricity to protect the protagonist's SOUL from Flowey's bullets. In the subsequent battle against Asriel Dreemurr, Alphys's Lost Soul uses some of Mettaton EX's attacks.
- In the game's strings in the part where the answers to Mettaton's quiz of "who Dr. Alphys has a crush on," it says "LOOLLLL IF YOU CAME TO THIS PART OF THE CODE TO SEE WHO I HAVE A CRUSH ON YOURE OUT OF LUCK." This is a joke hidden in the game's code as Alphys's crush is clearly Undyne, and she is not mentioned in that section of the code.
- The artbook reveals that Alphys was originally designed to be male, but Toby Fox quickly grew to dislike that idea so he added eyelashes onto her.
- In the epilogue, the game she is playing in the beach with Undyne is referred to in the sprites as a Gameboy.
- ↑ Toby Fox [tobyfox] (September 20, 2015). "personal pronunciation for some undertale characters (dont care if u say diff)" Archived April 8, 2016.
- ↑ "WHY WOULD SOMEONE OUTFIT AN AMUSEMENT ROBOT... WITH BRUTAL COMBAT CAPABILITIES? SIMPLE. TO IMPRESS MR. ASGORE DREEMURR, OF COURSE! OR AS ALPHYS CALLS HIM... 'MR. DREAMY.'" - Mettaton
- ↑ "Hey, why didn't you tell me the queen was so cute?" - Alphys
- ↑ "UNDYNE!!! I CAN'T TAKE THIS ANY LONGER!!! I'M MADLY IN LOVE WITH YOU!!! HOLD ME, UNDYNE!! HOLD ME!!!" - Alphys
- ↑ "the families keep calling me to ask when everyone is coming home. what am i supposed to say? i don't even answer the phone anymore." - Alphys, True Lab ENTRY NUMBER 19
- ↑ "i spend all my time at the garbage dump now it's my element" - Alphys, True Lab ENTRY NUMBER 21
- ↑ "That's where I met Alphys for the first time!! I was looking for cool swords, when I saw her... Uh, standing there, staring into the abyss. She looked pretty... Um... ... contemplative." - Undyne
- ↑ "Actually, since you stepped out of the RUINS, I've, um... ...been "observing" your journey through my console. Your fights... Your friendships... Everything! I was originally going to stop you, but... Watching someone on a screen really makes you root for them." - Alphys
- ↑ "S-so, ahhh, now I want to help you! Using my knowledge, I can easily guide you through Hotland! I know a way right to ASGORE's castle, no problem!" - Alphys
- ↑ "Anti... anti-human combat features? Of c-course, when I saw you coming, I immediately decided... I have to remove those features! Unfortunately, I may have made a teensy mistake while doing so. And, um... Now he's an unstoppable killing machine with a thirst for human blood?" - Alphys
- ↑ "OH! OH! I KNOW THIS ONE!!! IT'S SNAIL ICE CREAM!!!!!!!! IN THE FOURTH CHAPTER EVERYONE GOES TO THE BEACH!!! AND SHE BUYS ICE CREAM FOR ALL OF HER FRIENDS!!!! BUT IT'S SNAIL FLAVOR AND SHE'S THE ONLY ONE WHO WANTS IT!!!!!!" - Alphys
- ↑ "It can do texting, items, it's got a key chain... I even signed you up for the underground's No. 1 social network! Now we're officially friends! Ehehehe!" - Alphys
- ↑ "ALPHYS updated status. for now i gotta call up the human and guide them =^.^=" - Alphys
- ↑ "This p-puzzle is kinda... um... timing- based. Y-you see those switches over there? Y-you'll have to press all three of them within 3 seconds. I'll t-try to help you with the rhythm!" - Alphys
- ↑ "I don't really... Like giving away puzzle solutions. But if you need help, just call me, ok?" - Alphys
- ↑ "Actually, wait, I have an idea! Let's be friends on UnderNet! Then you can just ping me when you need help! Wait, we're already friends, aren't we? I signed you up, didn't I? You've been reading my posts the whole time... Well! I hope! You agree with me! About Mew Mew 2!" - Alphys
- ↑ "F-f-fortunately, I might have a plan! When I was upgrading your phone, I added a few... features. You see that huge button that says... "JETPACK"?" - Alphys
- ↑ "N-no...! I must not have added enough fuel! D-darnit... I'm sorry... Even when it's something like this, I... I still...! I still..." - Alphys
- ↑ "UNFORTUNATELY, THAT MEANS NO ONE IS WATCHING THIS RIGHT NOW. I'M NOT GOING TO DESTROY YOU WITHOUT A LIVE TELEVISION AUDIENCE!! LOOKS LIKE YOU'VE FOILED ME ONCE AGAIN, THANKS TO THE BRILLIANT DR. ALPHYS!!!" - Mettaton
- ↑ "Wow! We... we did it!! We... we really did it!!! Great job out there, team!" - Alphys
- ↑ "I work at the CORE. The inside is a maze made of swappable parts... That means we can shuffle the layout at will." - Hotland NPC
- ↑ "Why didn't you head to the right...? C-C'mon... Y-you trust me, d-don't you?" - Alphys
- ↑ "SHE DESPERATELY WANTED TO BE A PART OF IT. SO SHE DECIDED TO INSERT HERSELF INTO YOUR STORY. THIS SCENARIO, WHERE SHE 'SAVES' YOU FROM ME, WAS HER CREATION. EVEN NOW, SHE IS WAITING OUTSIDE THIS ROOM. DURING OUR 'BATTLE,' SHE WILL INTERRUPT. THEN SHE WILL PRETEND TO 'DEACTIVATE' ME, 'SAVING' YOU ONE FINAL TIME. FINALLY. SHE'LL BE THE HEROINE OF YOUR ADVENTURE. FINALLY. SHE'LL BE SOMEONE SOMEBODY ACTUALLY LIKES." - Mettaton
- ↑ "But, you know how Mettaton always faces f-f-forward? That's because there's a switch on his backside. S-s-so if y-y-you c-c-can turn him around... um... And, umm... press th-th-th-the switch... He'll be... um... He'll be... Vulnerable." - Alphys
- ↑ "...thank GOD, it's just the batteries." - Alphys
- ↑ "H... hey... D... don't worry about it... I can always... I can always build a different robot!" - Alphys
- ↑ "W... Wait! I mean, um... I... I was just going to... ...um... Say goodbye, and... I can't take this anymore. I... I lied to you." - Alphys
- ↑ "If you want to go home... You'll have to take his soul. You'll have to kill ASGORE." - Alphys
- ↑ "Oh my god. Oh no. That's adorable... And I h-had no idea you, um, wrote that way!" - Alphys
- ↑ "R... roleplay? ...That actually sounds kind of fun!" - Alphys
- ↑ "I... I just wanted to impress you! I just wanted you to think I was smart and cool." - Alphys
- ↑ "ALPHYS AND I FINISHED OUR TRAINING EARLY. VERY EARLY. SO I SENT HER HOME. VERY HOME." - Papyrus
- ↑ "This isn't anyone else's problem but mine. But if you don't ever hear from me again... If you want to know 'the truth.' Enter the door to the north of this note. You all at least deserve to know what I did." - Alphys's note
- ↑ "Every day I'm scared... Scared what will happen if people learn the truth on their own. They'll all get hurt because of me.." - Alphys
- ↑ "Sorry about that... They get kind of sassy when they don't get fed on time." - Alphys
- ↑ "Now, I've changed my mind about all this. I'm going to tell everyone what I've done. It's going to be hard. Being honest... Believing in myself..." - Alphys
- ↑ "Uh, h-h-hi! (THERE'S TWO OF THEM???)" - Alphys
- ↑ "Y-yeah, ASGORE!! Undyne's totally right about that fish thing! S-sometimes you've just got to, uh... S-stop going after furry boss monsters and, uh... J-just get to know a really cute fish...?" - Alphys
- ↑ "OH MY GOD! WILL YOU TWO JUST SMOOCH ALREADY!? THE AUDIENCE IS DYING FOR SOME ROMANTIC ACTION!!" - Mettaton
- ↑ "Papyrus... YOU called everyone here, right? Well, besides, uh, her. Uh, anyway... If I got here before you... How did you know how to call everybody?"- Alphys
- ↑ "Technically, it's impossible for you to beat him... B-but... Somehow, I know you can do it!!" - Alphys
- ↑ "I heard Dr. Alphys told the king and queen the awful things she'd done. The king felt so bad that he didn't know. He gave her a big hug. Then the queen fired her. Now we don't have a Royal Scientist anymore..." - Snowdin NPC
- ↑ "No, I should be honest!! I'm gonna stay inside and watch anime like a total loser!" - Alphys
- ↑ "(Oh My God?) (Frisk. Please.) (Help me explain what anime is to Asgore.)" - Alphys
- ↑ "Golly. Were those two robots... ...kissing? Boy! Technology sure is something, isn't it?" - Asgore
- ↑ "But when Undyne called, with crazed desperation in her voice... I... I realized I had to do something. Even if it meant everybody would... Have to learn the truth about me. It's strange. You know? Even after all the bad things I did. People treated me like a hero." - Alphys, Neutral Route ending
- ↑ "DECIDING NOT TO FIGHT YOU. MY MY, SHE REALLY IS THE ONLY SMART ONE, ISN'T SHE?" - Mettaton
- ↑ "Last week I posted that advertisement for my Human Fanclub. Today was our first meeting. Only one other person came." - Mettaton, diary entry in his house
- ↑ "now that mettaton's made it big, he never talks to me anymore. ...except to ask when i'm going to finish his body. but i'm afraid if i finish his body, he won't need me anymore... then we'll never be friends ever again." - Alphys, True Lab ENTRY NUMBER 11
- ↑ "...thank GOD, it's just the batteries. Mettaton, if you were gone, I would have... I would have... ..." - Alphys
- ↑ "REALLY THOUGH. I REALIZED I WAS... NOT THE GREATEST TO HER. SO I WENT TO APOLOGIZE. AND, TO ASK HER TO HELP ME RULE. BUT I COULDN'T FIND HER. TRUST ME. I LOOKED." - Mettaton, Mettaton Neutral Route ending
- ↑ "I just wanted you to think I was smart and cool. That I wasn't some... nerdy loser." - Alphys
- ↑ "SHE SCRAWLS HER NAME IN THE MARGINS OF HER NOTES. SHE NAMES PROGRAMMING VARIABLES AFTER HER. SHE EVEN WRITES STORIES OF THEM TOGETHER... SHARING A DOMESTIC LIFE." – Mettaton Quiz Show
- ↑ "Alphys's history books made me think humans were cool... ...with their giant robots and flowery swordswomen." - Undyne
- ↑ "Now this chilly pink stuff that Alphys makes me... THAT rules!!!" - Undyne
- ↑ "Alphys helped measure out the mud tiles for this puzzle. It was a lot of work, but we got to make sand castles after. We're a good team. She's great at building them... And I'm great at wrecking them!!" - Undyne
- ↑ "I'm sorry. I j-just figured, y-you know... It'd be f-fun to go on like, a cute, kind of... Pretend date with you? T-to make you feel better? Well, it sounds even worse when I put it like that." - Alphys
- ↑ "You know. Just daydreaming here. But... I really should have killed you when I had the chance." - Alphys
- ↑ "WHY WOULD SOMEONE OUTFIT AN AMUSEMENT ROBOT... WITH BRUTAL COMBAT CAPABILITIES? SIMPLE. TO IMPRESS MR. ASGORE DREEMURR, OF COURSE!" - Mettaton
- ↑ "Just think about how cute they must have been together. It's quickly becoming my number one ship of all time. Tori and Gorey..." - Alphys
- ↑ "Ehehe... Ehehehe... AHA! AHAHAH! HA!! HA!!! Oh, Toriel. You have NO idea." - Alphys
- ↑ "A woman can dream though, right? And write fanfiction. A LOT of fanfiction." - Alphys
- ↑ "Oh my God. Alphys. She used to live on our street." - Bratty
- ↑ "Oh my god, ALPHYS. She was like a big sister." - Catty
- ↑ "So, like, I'm pretty sure she... Made Mettaton to, like, totally impress him. A robot with a SOUL... That's, like, SUPER relevant to his hobbies!" - Bratty
- ↑ "But nobody's, like, seen anything from her yet. Or... her at all... She must, like, just stay in her lab all day. Like, live a little, girl." - Catty
- ↑ "Alphys just came here and she's taking us... Someplace super duper safe!" - Note at Bratty and Catty's store
- ↑ Anyways, now I'm working as Alphy's lab assistant... – Undyne in the Neutral family ending
- ↑ "WAIT, ALPHYS, I DIDN'T KNOW YOU KNEW SANS." - Papyrus
|Main Characters||Flowey • Toriel • Sans • Papyrus • Undyne • Alphys • Mettaton • Asgore Dreemurr • Frisk • Chara|
|Ruins Enemies||Dummy • Froggit • Whimsun • Moldsmal • Loox • Vegetoid • Migosp • Napstablook|
|Snowdin Enemies|| Snowdrake • Chilldrake • Ice Cap • Gyftrot • Doggo|
Dogamy and Dogaressa • Lesser Dog • Greater Dog • Jerry • Glyde
|Waterfall Enemies||Aaron • Moldbygg • Woshua • Temmie • Mad Dummy • Shyren|
|Hotland Enemies||Vulkin • Tsunderplane • Pyrope • Muffet • Royal Guards • So Sorry|
|CORE Enemies||Final Froggit • Whimsalot • Astigmatism • Madjick • Knight Knight|
|Amalgamates||Memoryhead • Endogeny • Reaper Bird • Lemon Bread • Snowdrake's Mother|
|Hard Mode-only enemies||Parsnik • Moldessa • Migospel|
|Vendors||Nice Cream Guy • Snowdin Shopkeeper • Gerson • Tem Shop • Bratty and Catty • Burgerpants|
|Other Characters|| NPCs • Monster Kid • Annoying Dog • River Person • Eight Humans • Asriel Dreemurr|
W. D. Gaster • Lost Souls