Frankenstein's creature might have a monstrous appearance, but that doesn't necessarily make him a monster. I think during Shelley's day he would have been considered a monster. Certainly, she intended him to be an unnatural creation. Modern readers aren't likely to view the supposed monster in the same light. Personally, I think he started out as innocent as a child. He eventually commits some monsterous acts, but he was certainly provoked. The questions is whether or not provocation excuses the action. He is certainly not guiltless, but I do not think he is a monster. Generally, I think someone is a monster when they can do terrible things and not feel guilt or remorse. Frankenstein's creation does feel guilt and remorse. Perhaps the real monster is Frankenstein himself.