Living Dead Beat

A Deadbeat is defined by Webster as "one who persistently fails to pay his debts or way." The word was coined in the late 1800's when railroad workers noticed that loaded freight cars made a different beat over the track-joints than cars that weren't carrying a load. The empty cars made a "dead beat" which meant they weren't paying their way. By the beginning of the 20th century "deadbeat" came to encompassed people who failed to carry their share of the load also.
^^ google PWNS all