Pet Rocks were a FAD in the 1970s that involved rocks being sold as pets. The CRAZE was started by advertising executive Gary Dahl, who marketed the rocks as low-maintenance pets. The FAD quickly spread and became popular among children and adults alike. The CRAZE eventually died out, but the term 'pet rock' has become a part of popular culture. The crossword solutions for the term 'pet rocks' are 'CRAZE' (5 letters) and 'FAD' (3 letters).