The phrase "am whipping boy" has a negative connotation, referring to someone who takes the blame or punishment for the mistakes or faults of others. Synonyms for this phrase include "scapegoat," "fall guy," "patsy," and "sacrificial lamb." These words all convey the idea of an innocent person being unfairly blamed or punished for the actions of someone else. Other related terms might include "victim," "target," or "martyr." While there may be some subtle differences in meaning between these various synonyms, they all share the common theme of someone being unfairly held responsible for something that was not their fault.