Over nine feet tall and still growing by the time of his death, Wilbur wore voluminous clothes in an effort to disguise his continuously-degenerating form. Although his hands and face could pass for a human's the skin of his upper body was scaled like that of a reptile, with armour plating reminiscent of a crocodilian across the chest. His skin was covered with a thick coat of black fur and from his abdomen grew a forest of greenish-grey appendages tipped with red-rimmed, sucking mouths. Each of his hips sported what seemed to be a rudimentary eye, and in the place where some animals have a tail, Wilbur had a strange trunk-like protrusion resembling an undeveloped throat. He had legs described as being akin to a dinosaur's that terminated in malformed, clawed hooves, and in place of blood had a stinking, sticky, greenish-yellow ichor.
Born to Lavinia Whateley and an unnamed father (who, as it turned out, was the Outer God Yog-Sothoth), Wilbur matured incredibly quickly, learning to talk at eleven months, and appearing as a boy of fifteen at only four-and-a-half years old. Disliked by the other children of Dunwich, and actively attacked by their dogs, Wilbur was home-schooled by his grandfather for the first few years of his life. There, the 'Wizard Whateley,' as his grandfather was known locally, taught him all manner of dark magics, and the worship and summoning of forbidden entities.
What nobody knew was that Wilbur was not the only child born to Lavinia; Wilbur had a brother, although this creature, who would come to be known as the Dunwich Horror in later years, had no semblance of humanity whatsoever.
Wilbur looked after his brother alone in the years following the deaths of his mother and grandfather, but also continued with his studies of the dark arts. After being refused a loan of the Miskatonic University's copy of the Necronomicon, Wilbur broke in to the University with the intent of stealing it. Unfortunately for him, one of the guard dogs caught him in the act and killed him. Once dead, Wilbur's body quickly decomposed into little more than a foul-smelling liquid.
Without the care of his brother, the Dunwich Horror grew hungry and began its now-infamous rampage across the countryside of Massachusetts.
- The Dunwich Horror (1929), by H.P. Lovecraft.