What was the name of McDonald's character who stole hamburgers?

The McDonald's character who stole hamburgers was called the Hamburglar.

The Hamburglar became part of the McDonaldland cast and was defined by his attempts to grab hamburgers. Early versions of the character had a more sinister appearance, including a striped outfit and exaggerated features. McDonald's later redesigned him as a younger, friendlier character for children's advertising.

His role created a simple recurring story: the Hamburglar wanted hamburgers, while Ronald McDonald and the other characters tried to stop or outsmart him. This kind of repetition made the character easy for children to recognize across commercials, packaging, and merchandise.

The Hamburglar is often mixed up with Grimace, who was another McDonaldland character. Grimace was not the hamburger thief. Mayor McCheese was a separate character with a cheeseburger-shaped head and a civic role in the fictional world.