I wonder what would you normally call someone who has a chip on their shoulder informally? (What I am looking for can be considered as an offensive idiom/expression/adjective by most people.) Such people have many complexes and most of the time treat others in an offensive, aggressive or unfair manner, because there is something eating them from inside. Psychologically they have been treated in the past very bad once or for a long time, and they want to revenge in this way; because deep down inside they consider all the surrounding people guilty.
Mother: Did you go to that department today and talk to the director?
Daughter: No, mom! And I won't go. They're a bunch of ____________
I wonder what would you use in the blank?