A case of the black ass
What is the origin of the phrase "a case of the black ass". Does it mean that a person does not want to work? Is this a recially derogatory phrase?
This phrase isn't common where I am (western U.S.); at least, I've never heard it. If the context where you found it suggested laziness, then yes, it might be racially derogatory.
I never heard it, either. Midwest U.S. (and a few other regions...)