Not all monsters are evil

On some issues, Vampirella isn't represented as a monster. On some, she says herself she is a monster. I understand that she meant that (the author also) not all monsters are evil. But still, What is a monster? a unique predator? a form of life undiscovered? Well, if that is the case and a real Vampirella would land on our planet, she wouldn't be viewed as a monster, but as a female human with a different set of genetics. Still, on the issues of Vampirella, why the confusion? Is she a monster or not? On the earliest Issues by the Warren Publishing she was never portrayed as a beast or monster.