He founded and created the collectable toy Pet Rock—smooth stones from the city of Rosarito, Baja California, Mexico, in the mid-1970s—which was successful enough to make him a millionaire.
Dahl soon decided that he could turn the idea into a profitable novelty; in the weeks that followed, he wrote a 36-page instruction book, got two people to invest in the product, and purchased "Mexican beach stones".
[4] The craze made Dahl a minor celebrity; it was widely covered in the media, he was on The Tonight Show twice, and received so many calls he later said he “taught my P.R.
[3][4] From the proceeds of his "pets," in 1977 Dahl opened a bar in Los Gatos, California, which he jokingly named "Carrie Nation's Saloon.
In 2000, Dahl won the Bulwer-Lytton Fiction Contest,[3] the San José State University–sponsored competition that awards authors for crafting particularly bad "purple prose."