Grimace was first introduced by McDonald's in 1971. Early advertisements presented him as a more mischievous character sometimes called the Evil Grimace, with four arms used to take milkshakes.
The character was redesigned soon afterward into the large, purple, friendly figure most customers recognize. His simplified appearance made him easier for children to identify and paired him visually with Ronald McDonald and the Hamburglar in McDonaldland campaigns.
Grimace's exact species has never been officially defined in a consistent way; McDonald's has generally treated him as a fictional creature. That ambiguity has encouraged fan speculation, but it does not change the documented 1971 introduction or the character's role in the brand's family advertising.