Speedee was the McDonald's mascot used before the golden arches became the company's dominant corporate symbol.
Speedee represented the fast-service promise of the McDonald's Speedee Service System. The character appeared in early signs and advertising when the business was still building its identity around efficient hamburger preparation.
As the chain expanded, the golden arches became a more flexible and memorable symbol for restaurants, packaging, and advertising. Ronald McDonald later added a character-centered approach to family marketing, but he was not the original mascot.
The question is about the mascot that preceded the arches' dominance, not about McDonaldland characters. Grimace and the Hamburglar belong to the later fictional advertising world.