>>105643804It can't become furry. Furry is defined by exclusion. It describes something more than 50% but less than 100% animal, part human, not a monster, not an alien, not a robot, and not someone in a suit.
>>105643662If it's a female monster with human elements, an anthropomorphized monster with a form reminiscent of a human female, or a monster which can turn INTO a human female, it's a monster girl.
So the line starts at vampire/chimera/cyborg/frankenstein/pick your human female+something that makes her a monster and ends at monster with something that makes her a human female.
Greek Sphinx? Monster girl. Slimegirl? Monster girl. Shub-Niggurath? Monster girl.