The Half Made Thing is a short story written by T. E. Grau. It was first published in the 2014 anthology The Dark Rites of Cthulhu, edited by Brian M. Sammons.
Description[]
Young Eliot, whose father has been bewitched by a wealthy witch-woman named Marsila, moves into an enormous estate in Northumberland, England. Ignored by his father and mother-in-law, he spends his days alone, exploring his new home, and comes across a derelict watermill, within which dwells a disgusting, malformed creature. Befriending the monster, Eliot agrees to help it, and spends the next few months learning the ways of magic from it. However, the Half Made Thing has tricked the boy, and the spells he has been casting ultimately result in the Thing becoming it’s fully-formed, inhuman self, while Eliot transforms into a hideous abomination.