Grimace is the purple McDonald’s character known simply by that name.
Grimace first appeared in McDonaldland advertising in 1971. His original design was considerably different from the friendly, rounded character most people recognize: early advertisements portrayed him with multiple arms and a role connected to stealing milkshakes.
McDonald’s later redesigned Grimace into a large, soft-looking purple figure. The revised character became a friendlier member of the McDonaldland cast and was used in advertising aimed at children and families.
Grimace is sometimes described as a milkshake or another specific food, but McDonald’s has generally presented him as a character rather than a menu item. His changing design is one reason older and newer images can look surprisingly different.