Pet Rock creator Gary Ross Dahl became a millionaire from his rock sales in the 1970s. Each rock came in a special box (bottom left) with a detailed instruction manual. San Francisco Chronicle/AP hide caption

itoggle caption San Francisco Chronicle/AP

For the past 34 years, the William Grant Still Arts Center has held a Black Doll Show to showcase diverse dolls for children. The exhibit features dolls submitted by artists and collectors from around the country. Priska Neely/NPR hide caption

itoggle caption Priska Neely/NPR

A product image shows the new Research Institute playset from Lego, which features women in roles as three scientists. In January, the company was criticized by a girl who said all its female characters were "boring." Lego hide caption

itoggle caption Lego

At left is a reproduction of the original G.I. Joe action figure made in 1964. The doll on the right is a newer G.I. Joe model. Hasbro executive Donald Levine, who oversaw the action figure's creation, died last week of cancer. Anonymous/AP hide caption

itoggle caption Anonymous/AP

Mattel executives say they did not anticipate the runaway success of the goth-influenced Monster High brand when it debuted in 2010. Mattel hide caption

itoggle caption Mattel

Hasbro's pink Easy-Bake Oven is under fire for reinforcing gender stereotypes. Peggy Turbett /The Plain Dealer/Landov hide caption

itoggle caption Peggy Turbett /The Plain Dealer/Landov