Mac Tonight was the 1980s McDonald's mascot known for appearing with a crescent moon for a head.
McDonald's introduced Mac Tonight in 1986 in advertising designed to promote evening dining. The character wore sunglasses, a tuxedo, and a bow tie, and he sang a version of “Mack the Knife.” His crescent-moon head made him visually distinct from Ronald McDonald and the McDonaldland cast.
The campaign targeted adults and emphasized McDonald's as a place to visit at night. That positioning differed from the family-oriented fantasy advertising associated with Ronald and the other McDonaldland characters.
Mac Tonight is sometimes confused with the restaurant's long-running “I'm Lovin' It” identity or with earlier mascots. He was a specific advertising character from the mid-1980s, not a permanent replacement for Ronald McDonald and not the origin of the Golden Arches.