Grimace was the purple creature in McDonald's 1970s McDonaldland campaign.
Grimace was introduced as part of a group of fictional characters used to make McDonald's advertising more imaginative and appealing to children. His appearance changed over time, but the character became strongly associated with a large purple body, a friendly personality, and a simple, enthusiastic role in the McDonaldland world.
The character's earliest concept was different from the familiar friendly version. Grimace was initially depicted with multiple arms and a more mischievous presentation before the design was simplified.
The Hamburglar, Birdie, and Mayor McCheese were separate McDonaldland characters. Their names and costumes helped create a shared fictional setting, but none was the purple creature identified with Grimace.