Foaly is a fictional character in the Artemis Fowl series written by Eoin Colfer. He is the technical consultant to the Lower Elements Police (LEP). He is the most intelligent centaur on and under the Earth, considers himself to be an unappreciated genius, and is the inventor of most of the advanced technology possessed by the fairy world, rivaled only by Opal Koboi.
Little is known of Foaly's earlier life. There is no obvious indication of his age though he seems to be older than Holly Short. In Artemis Fowl, Foaly is said to have been designing transport pods for over a century, and in Artemis Fowl: The Lost Colony Holly states that she is only in her eighties. It is revealed in Artemis Fowl: The Arctic Incident that Foaly cannot dance well (four left hooves); and he is married to a centaur called Caballine, whom he is revealed to be dating in Artemis Fowl: The Lost Colony.
In The Artemis Fowl Files, in an interview with Foaly, he states that he has recently taken up line dancing. In Artemis Fowl: The Lost Colony he also shows a habit of singing "Riverbend" songs as he works under pressure, or it could be that he is in love with a female centaur. He also says that he enjoys watching videos or reading articles of himself, an example of the centaur's natural arrogance.
Foaly is the only fairy to think that perhaps Artemis Fowl II was one step ahead of the LEP the whole time, which, incidentally, he was. Eoin Colfer further develops Foaly's character and background in the next Artemis Fowl books.
In the second installment, Foaly is framed by former LEP commander Briar Cudgeon and the genius pixie Opal Koboi, who have wrongly accused Foaly of aiding the B'wa Kell (a goblin triad association) in their goal of LEP destruction. However, using Artemis's laptop- which had been left behind in his lab following an earlier visit-, Foaly is able to contact Artemis, Butler, Root and Holly for assistance, subsequently acquiring recorded evidence that Cudgeon was planning to betray Opal that caused the two of them to turn on each other at the last minute.
In the third, initially, he recognizes the emergency call and sends Holly to investigate, and then coaches her through the arduous healing that ultimately saves Butler's life. Later on, he illegally helps Artemis by giving him fairy technology to use against Jon Spiro and by playing the voice of the C Cube to help deceive Spiro.
In the fourth, he figures out that Commander Julius Root was killed by Opal Koboi rather than Holly Short as the footage seemed to suggest. He uses the Retimager, an invention from the second book that matches images with those on the retinas of one's eyes (allowing Foaly to effectively see what the person has seen, regardless of if they remember it), to discover that the Opal that is in a coma is in reality a brain-dead clone of Opal, thus giving Foaly evidence to persuade the LEPrecon to search for Holly Short. She was presumed dead and solely responsible for Root's death, though Foaly helped prove that she had in fact been framed.
In the fifth, he aides in infiltrating the Paradizo estate and reclaiming the kidnapped demon, N°1, from Minerva. He is also solely responsible for discovering the information about the Paradizo's in the first place, mostly because they had erased proof of their existence. He got married during the 3 year period that Holly was gone in the Lost Colony.
There is a short invention guide, including blueprints and images of some of Foaly's better known inventions, in Eoin Colfer's book, The Artemis Fowl Files. He also is rumored to be the administrator of 'www.horsesense.gnom', a fictitious fairy website.