Gold brick typically refers to someone who pretends to work while doing little or no work at all. However, there are several antonyms for gold brick, which represent individuals with different work ethics. The first antonym for gold brick is hard worker, a person who is diligent, dedicated, and puts in extra effort to accomplish tasks. The second antonym is go-getter, a person who is ambitious, driven, and takes the initiative to tackle new challenges. The third antonym is achiever, a person who sets goals and works hard to attain them. Finally, the fourth antonym is maverick, a person who thinks outside the box and challenges the status quo to achieve success.