This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Nasnas (Arabian)
In Arab folklore, the Nasnas is a monstrous creature. According to Edward Lane, the 19th century translator of The Thousand and One Nights, a nasnas is "half a human being; having half a head, half a body, one arm, one leg, with which it hops with much agility".
In Somali folklore there is a similar creature called "xunguruuf" or "Hungruf". It is believed it can kill a person by just touching them and the person would be fleshless in mere seconds. It was believed to be the offspring of a jinn called a Shiqq and a human being.