How harmful is a parody for the target brand? To address this question, the current study focuses on negative ad parodies created by amateurs and spread through social media. It examines the types of consumers for whom and contexts in which negative ad parodies will negatively affect attention, attitudes, purchase intentions, and intentions to pass along the ad. Using a purposefully designed print parody advertisements for McDonald’s and manipulating the level of humor and claim credibility, the authors find that ad parody is detrimental for the parodied brand if the parody is strongly credible and contains humor. High-committed consumers are not isolated from this detrimental effect. These findings have implications for both research and practice.