Born in the slums of Chicago in the early 1900's. Billy Byrne or 'The Mucker' was a thug, a drunkard, a thief and and all round bad guy. Although he followed a strict code of 'street ethics'. A powerfully built man, a crafty brawler and a very gifted boxer. Byrne was lethal in a fight. He ultimately surpassed his less than noble predilections and evolved into quite a heroic character throughout his 'two fisted' pulp adventures.