1) A person who acts like there on crack all the time and cant stop moving around.
2) An individual who cant help but injure themselves on a daily basis because they act like there on crack 24/7.
3)A tomboy girl who is annoying as hell and cant stop twitching and moving around. Always manages to hurt herself and others and laughs about. Who cant go more than a day with injuring herself in some new and inventive way.
****** was running around at work and ran into a tree. Shes such a crack-headed jackrabbit.
****** challenged the giant to a wrestling match. What is she on crack? yeah but shes fast like a jackrabbit maybe she'll last a couple minutes...... or not.