The London Monster was the name given to an alleged attacker of women in London between 1788 and 1790. First reports of the Monster appeared in 1788. According to the victims (most of them from wealthier families), a large man had followed them, shouted obscenities and stabbed them in the buttocks. Some reports claimed an attacker had knives fastened to his knees. Wikipedia
The definitive Wikipedia entry for London Monster. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/London_Monster