UNDERTALE/Alphys

Overview
Dr. Alphys is a female, reptilian monster that lives in the lab in western Hotland. She is a smart, shy scientist who took over for Gaster.

Apperance
Alphys is a yellow, reptilian monster who is almost the same height as the player. She is always hunched over for some reason. She wears a lab coat, glasses, and, during her date, wears a polka dot dress.

Personality
Alphys is shown to be shy. Like, REALLY shy. Fluttershy has nothing on her (if anyone gets the reference) when it comes to that. In some neutral routes, due to her shyness or other events caused by losing Mettaton, she becomes more reclusive or even goes as far as suicide (possibly by letting her body be melted by the Amalgamates and their determination in the True Lab). Other than her shyness, she is a HUGE nerd.

Pacifist Route
After the quiz show Mettaton gives, Alphys upgrades your phone and proceeds to help the player get through the Hotlands. She doesn't do this intentionally, due to the fact that she hates giving the answer outright, but she updates her status with the answers until she realizes you've been reading them.

Neutral Route
It's the same as the Pacifist Route unless you are aborting the Genocide Route in the Hotlands or decide to kill Mettaton, in which case, she proceeds to disappear (possibly due to her commiting suicide) at the end of the route.

Genocide Route
The True Lab is inaccessible due to the fact that Alphys hid everyone there. She doesn't know that Mettaton is still up there...

True Lab
The True Lab is the only place in-game where Chara's history is found (other than the flashbacks in Asriel's battle). It is closely related to Alphys's DETERMINATION studies.

Trivia

 * Alphys is an anagram of "shy pal"; this could be where her name came from.
 * When attempting to name the Fallen Human "Alphys," the response becomes "D-Don't do that." and prevents the name from being used.
 * However, when naming the fallen human "Alphy" (without the last letter), the game will respond "Umm, okay?.." and this name can be used.
 * Before the protagonist enters the True Lab, there is a note in the trash can that reads "I KNOW WHAT YOU DID."
 * This was probably written by Flowey
 * Alphys is the only major monster in the game who the protagonist cannot fight and, therefore, kill.
 * This causes her true combat capabilities to be unknown.
 * The only way to see her fight is in Asriel's battle, where she uses Mettaton's attacks, or by hacking, which crashes the game, due to Alphys not having attacks.