rattle-bones

rattle-bones

slang A person or animal that is extremely skinny, especially so that their bones are visible through their skin. They gave me this worthless old rattle-bones of a horse to ride. I didn't think it would even make it all the way to Las Cruces. I can't believe you let a skinny little rattle-bones like him beat you in a fight.
Farlex Dictionary of Idioms.

rattlebones

n. a nickname for a very skinny person. (Also a term of address.) Hey, rattlebones, come over here a minute.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • rattlebones
  • (as) skinny as a rail
  • rail
  • skinny
  • skinny as a beanpole
  • (as) skinny as a beanpole
  • beanpole
  • bastardly gullion
  • (as) worthless as tits on a boar (hog)
  • be (as) thin as a rail