The purple, pear-shaped McDonald's mascot that first appeared in advertising in 1971 was Grimace.
Grimace was introduced as a McDonaldland character during the early 1970s. His original portrayal was different from the friendly, simple character most people recognize today: early advertisements presented him as a more mischievous figure associated with stealing milkshakes.
McDonald's later redesigned Grimace as a large, purple, gentle character. That friendlier version became part of the regular McDonaldland cast alongside Ronald McDonald, Mayor McCheese, and other mascots.
Grimace is often confused with the Hamburglar because both began as mischievous characters in the same advertising universe. Their designs and roles were distinct, however. Grimace's defining visual traits are his purple color and rounded, pear-like shape.