To be 'scrawn and bones' is to be so skinny that your body literally constists of only skin and bones. When one is skinny, they are thought to be scrawny- thus the origin of "Scrawn and bones".
When a person has had enough bschild's play from someone and won't take it or waste their time dealing with it anymore to the point that they call the other out to become better or they're walkin. Usually done in a feisty but playful manor so as to not offend but give an opportunity to learn and grow. But if not up to speed they'll get left behind.
A game played by young children around the age of 12. Children partaking attempt to remove bones from their bodies with as little health consequences possible. The winner is chosen by either the largest or most plentiful amount of bones and dubbed the bone lord.