Alphys
Alphys is a character created by Toby Fox, appearing in the video games Undertale and Deltarune. In Undertale, she serves as the Royal Scientist of the Underground under King Asgore, having gained her position by constructing a physical body for the robotic performer Mettaton. In the alternate world of Deltarune, she works as a high school teacher in the Light World, overseeing the class attended by Kris and Susie. She is a yellow, reptilian monster who possesses immense technical intelligence alongside a deep passion for human pop culture and animation.
Overview
Alphys is a character created by Toby Fox, appearing in the video games Undertale and Deltarune. In Undertale, she serves as the Royal Scientist of the Underground under King Asgore, having gained her position by constructing a physical body for the robotic performer Mettaton. In the alternate world of Deltarune, she works as a high school teacher in the Light World, overseeing the class attended by Kris and Susie. She is a yellow, reptilian monster who possesses immense technical intelligence alongside a deep passion for human pop culture and animation.
Appearance
Alphys is a small, yellow-skinned monster with a reptilian or dinosaur-like structure, standing at roughly the same height as the human protagonist. She features dark eyes, prominent front teeth, and wears round eyeglasses. Her primary outfit consists of a white lab coat, though she switches to a black dress decorated with white polka dots for special occasions. In Deltarune, her attire includes a necktie.
Personality
Alphys is exceptionally introverted, timid, and prone to severe stuttering when communicating with others. She struggles with intense self-doubt and feelings of inadequacy, often carrying deep remorse for past errors. Despite her social anxiety, she displays unbridled enthusiasm for human pop culture, comics, and animation, becoming remarkably talkative whenever discussing her favorite media franchise, Mew Mew Kissy Cutie. She maintains a gentle and compassionate disposition toward those around her, though she is easily intimidated by aggressive or unruly individuals.
Abilities
Alphys is a highly skilled engineer and scientist. She successfully built the physical body for the robot Mettaton and managed the complex power grids and security apparatus of the Core. Furthermore, she can rapidly upgrade handheld technology, transforming a basic phone into a device capable of text messaging, network browsing, and remote inventory access. In direct conflicts, her defensive magical patterns closely resemble the combat style of Mettaton.
Background
In Undertale, Alphys was appointed as the Royal Scientist by King Asgore following the disappearance of her predecessor, earning the role after constructing a functional body for Mettaton. Operating from her laboratory in Hotland, she monitored the human protagonist's journey through subterranean security cameras and offered assistance across their travels. In Deltarune, she resides in the Light World, where she secured a teaching position with help from Toriel and now manages a classroom of local youth.
Relationships
Alphys harbors romantic feelings for the Royal Guard captain, Undyne, a dynamic that grows into a close partnership. She maintains a respectful relationship with King Asgore, who appointed her as Royal Scientist and frequently shares her interest in human media and superhero comics. She holds a complex bond with Mettaton, having constructed his robotic vessel to boost her own confidence. In Deltarune, she enjoys a warm friendship with fellow teacher Toriel and acts timidly around her rebellious student Susie.
Trivia
The letters in the name Alphys form an anagram for Shy Pal, reflecting her timid nature. Entering her name during the character creation screen of Undertale prompts a flustered refusal that prevents the player from proceeding, whereas the shortened version Alphy is accepted. In the town alleyway, she leaves behind bowls of milk for an unseen cat named MewMew, which is later revealed to be secretly consumed by Susie.
