Alphys in a major character in Undertale. She is a reptilian monster with a keen intellect and a passion for scientific research. Dr. Alphys is responsible for some of the Underground's greatest technological developments, such as the sentient robot-turned-televsion star known as Mettaton. In light of her impressive accomplishments, Asgore granted Alphys the title of "Royal Scientist," after which she became renowned as the leading scientific mind in the Underground. However, Alphys is also extremely shy and has great difficulty coping with social situations. Her inability to properly express her romantic attraction towards several of Undertale's other characters, including the player, is a frequent source of comic relief.
Alphys spends most of her time ostensibly conducting research at her laboratory in Hotland. She also frequents Waterfall's garbage dump as her primary source for scrap metal and other discarded human artifacts. Since discovering several videos and comic books that had washed down from the surface world, Alphys has also developed an interest in anime and manga.
Undertale developer Toby Fox has confirmed that Alphys' name is correctly pronounced "al-feez".