"Some day yew folks'll hear a child o' Lavinny's a-callin' its father on the top o' Sentinel Hill!" - Old Whateley
The Dunwich Horror is the child of the human, Lavinia Whateley, and the Old One, Yog-Sothoth. It was conceived to free the Old Ones so they may reclaim the earth. Its existence was kept secret by its grandfather, mother, and eventually its twin brother, Wilbur Whateley. He fed on cattle growing up, gradually draining them of blood before ultimately devouring them completely. The near-insufferable stench of him kept away most passersby.
On September 9th the creature broke free from the Whateley farmhouse, littering the hillside with wooden planks soaked with an odd viscous substance. Barrel-sized tracks were found leading to a meadow where half a herd of cows were drained of blood.
In his natural state he is invisible to the human eye but a magical spell can render it visible.
Its final words were a cry of mercy to his father, who immediately struck him down with a bolt of lightning.