The Mud People, or humans, are a group of beings who live on the surface of the Earth, having ousted the fairy civilization long before.
They are considered by the People to be generally stupid, cynical, and bellicose, but some, such as Artemis Fowl II, Butler, and Minerva Paradizo, are even considered threats. It is unknown why the fairies call humans "Mud Men"; this may result from the fairies' conception that uncivilized, low-tech people are nothing more than cave-men, thus mud men, and that they are filthy in comparison to fairies. Captain Holly Short gives a clue to this nickname in the first book, thinking, "Of course the Mud People didn't live in the mud anymore," a reference to the time of cavemen. Fairies, having long lives, would easily remember this most simple of human times, and give them a nickname that stuck through the years. Also since most fairies have live most of their lives underground, and haven't even seen a mud-men, most people probably even thought they still live in the mud. Thus, it can be a historical insult as well as a jab at the People's relative technological advancement. They once had their own magic, but they lost the power to manifest it. So far the only human to have magic was Artemis Fowl II. He obtained it at the end of the fifth book, but he lost it at the start of the sixth book.