In the 80's I recall reading a book (possible series) about an alien (i believe he was either human like or could disguise himself as human) that was sent to Earth to survey/scout the planet fr a future invasion. During this time he "blends" in, I remember he had advanced technology that he used to regenerate limbs/change fingerprints etc (he did work for the mafia to 'change identities' for the criminals)........he pretty much set up business for himself. In the end he liked Earth and told his people there was nothing here I think.
Sorry to be so vague, I also believe at the time I read it it was an older book.
Sorry to be so vague, I also believe at the time I read it it was an older book.