Dr. Alphys is a character from Undertale. She is the royal scientist for Asgore. She lives in Hotland, and is best known for creating Mettaton and The Amalgamates.
The Human meets Alphys in Hotland. She pretends Mettaton is a killer robot, in hopes of pretending to save the human and becoming their friend. This backfires, as Mettaton reveals the plan, locks Alphys out, and attempting to kill the human. During the True Pacifist route, she shows you the True Lab. This is where her failed determination experiments took place. It's revealed that she created the Amalgamates from monsters that had "fallen down" and she injected them with determination. It's also revealed that she created Flowey.