Grimace was designed as a purple, amorphous companion to Ronald McDonald.
McDonald's introduced Grimace in 1971 as part of the McDonaldland advertising world. His earliest portrayal was different from the friendly, simple character familiar from later decades: he initially had multiple arms and was associated with stealing milkshakes. McDonald's subsequently changed the design and personality, presenting him as a large, purple, childlike companion.
The redesign helped make Grimace more suitable for family advertising and live appearances. He became one of the most recognizable McDonald's characters, appearing with Ronald, the Hamburglar, Birdie, and other figures in commercials and promotional material.
Grimace is often confused with the Hamburglar because both were introduced as McDonaldland characters. Their roles were different: the Hamburglar was a mischievous burger thief, while Grimace evolved into a friendly companion. Grimace's purple color and rounded shape became central parts of his later branding.