McDonald's introduced Grimace in 1971 as a character in its advertising.
Grimace was originally presented as an antagonist called Evil Grimace. Early versions had four arms and were associated with stealing customers' milkshakes. The character was later redesigned with two arms and a friendlier personality, becoming one of McDonald's best-known mascots.
Grimace joined the wider McDonaldland group, which included Ronald McDonald, the Hamburglar, Birdie, and other advertising characters. His purple color and simple shape helped make him especially recognizable in print, television, packaging, and merchandise.
A common mix-up is to associate Grimace's earliest appearance only with his later friendly role. His 1971 debut predates the modern version audiences usually remember.