A "pet rock" is a novelty item that became popular in the 1970s. It consists of a smooth rock sold in a cardboard box, often with air holes and straw for comfort. The concept was created by Gary Dahl, who marketed it as a low-maintenance pet that requires no feeding, grooming, or walking. The pet rock was a humorous response to the demands of traditional pet ownership. It quickly became a fad, with millions sold in a short time. The simplicity and absurdity of the idea captured the public's imagination, making it a memorable part of pop culture history.