A mad scientist, Always carrying nail guns. She began an internship with Riverperson (a former Royal scientist) and discovered her genius abilities. a Riverperson conducted an experiment with her, but little is known about it. Alphys is mostly the basis for her experiments. Undyne is the only monster who can handle Alphys as she pleases. Undyne might look quiet and gentle, but she hides her twisted desires easily. Sadly, Papyrus avoids her because she reminds him too much of Riverperson.