Sui generis
In local government, a "sui generis" entity is one that does not fit with the general scheme of local governance of a country. For example in England, the City of London and the Isles of Scilly are the two "sui generis" localities, as their forms of local government are both (for historical or geographical reasons) very different from those of elsewhere in the country. 
In a press conference during which reporters were trying to analyse his political personality, Huey Long said, "...say that I am "sui generus", and let it go at that."
Miss Peregrine's Home for Peculiar Children
Otherwise known as "syndrigast" (a word meaning "peculiar spirit" in the Old Peculiar language, which is in turn the author's adaptation of Old English, or Anglo-Saxon language), peculiar folk are a branch of humanity possessing a second soul which manifests itself in strange ways such as abnormal characteristics and abilities commonly referred to as "peculiarities". Very rarely are peculiar children born to peculiar parents as the essence or gene of peculiarity often skips entire generations, making peculiar population vastly less than that of normal people.