endemic vs rare as hen's teeth

endemic

• Peculiar to a particular area or region; not found in other places. 

• Native to a particular area or culture; originating where it occurs. 

• Prevalent in a particular area or region. 

• A disease affecting a number of people simultaneously, so as to show a distinct connection with certain localities. 

• An individual or species that is endemic to a region. 

rare as hen's teeth

• extremely uncommon