- You may be looking for the category for pages conjecturally named with demonyms.
Demonyms are those attributive nouns or adjectival nouns which describe the location from which a being originates. They aren't the same thing as species names, even though species are often named after the place from which they came. Generally, demonyms are more specific, geographically, than species names. Examples of demonyms include "Bristolian", "Liverpudlian" and "American".
This category is only for those articles which focus on defining a word that is known to be a demonym. It's not for species names that are demonymic or conjecturally demonymic. For instance, this category is not for Tivolian, because that's a conjectural title based upon the planet Tivoli. But it is for Mondasian, because that article is about how the word is used to describe people from Mondas. Generally speaking, if the term refers to only one thing, it shouldn't be in this category. But if the term can mean a lot of different things — e.g. all things from a particular location — then it probably should be here. Certainly, if the term does not describe a single species — like Scot, Venusian, or European — it belongs here.