I mean, from what we know he is considered a weirdo, and the number 3 here just got taken out by one so I assume no-one knows about them because everyone who sees them dies.seems like the mc shoulda brought up cuting off their head wont do the deed
also that guy cant be THAT old you're telling me no one believed the number 1 that there ar ehuman chimeras or something
or maybe its just not common knowledge so as to spread panic