A midget.
You are not allowed to use midget anymore but it means the exact same thing. A human of normal proportions that is much smaller then normal.
Dwarfism, which is occasionally used interchangeably and incorrectly, is the result of genetic abnormalities and they often has health problems. A midget usually just has a malfunction of the pituitary gland. It has been treatable with HGH since the 80s which is why you rarely see midgets anymore in developed countries.
I don’t know, I think most short people would be rather called dwarf or midget, rather than “homunculi”, sounds like a homosexual flower.