It's is OK to to say that frankensteins monsters name is Frankenstein
Sometime if you say this, Internet guy will come along and say 'oh but that is not the monster name, that is the scientist guys name'
But this frankenstein monster is creation of baron frankenstein, he is like his son. They make a comment about this in film called Son of Frankenstein. But this monster guy is bigger than life character, like some super hero or villain, so he will obviously have one name, like Prince, because it suit him more than call him Alan Frankenstein or whatever
Also if you look at this monster guy you can just see from looking him that frankenstein is his name
So you can see why I am right.