A person, animal or plant that lives or is often found in a certain place or region.
1) I saw one of those muscle-bound denizens of the gym.
2) The polar bear is an iconic denizen of the Artic region.
Middle English denizeine, from Anglo-French denisien, denzien which means 'inhabitant' , 'inner part' or 'inner'.
familiar, frequenter, habitué, haunter, rat, regular