Described as having clawed hands, eyes like balls of fire and other diabolical physical aspects, he was blamed for a series of incidents between around 1837 and 1872 - although he continued to be sporadically reported into the 20th century and is still occasionally linked to what are otherwise reported as UFO incidents.
Research by Mike Dash has uncovered a number of features of Jack's reign that most accounts have missed. It took some time for his appearance to coalesce into the image we have today. Prior to the first 'canonical' appearance at Clapham Common, reports were already circulating throughout the outskirts of London of various entities attacking strangers which shared several characteristics with Jack.
The Times of January9th and 11th 1837 reported attacks in Barnes by an 'imp' or 'devil' which was bizarrely reported as being in the shape of a large white bull. Over the following months, similar reports came in from throughout London - with Jack variously appearing in the form of a 'ghost' a 'devil' and a 'bear'.
The nature of these reports show just how contradictory early descriptions were until 'Jack' had become established more firmly in the public imagination. A carpenter in Cut Throat Lane, Isleworth reported that he had been attacked by a ghost in white "armour" and red shoes, who had been joined by two more entities when he fought back.
As in many cases, the British are unable to refrain from dragging aristocrats into the frame (see some of the more outlandish Jack the Ripper 'suspects' for examples of this tendency) and the 3rd Marquis of Waterford was thought by some to be the prankster behind the early attacks - although his death in 1859 would seem to rule him out of the later appearances. The Marquis' generally loutish behaviour is also claimed to have provided the inspiration for the phrase 'painting the town red'.