Mac Tonight was the crescent-moon lounge-singer character introduced in McDonald's advertising in 1986.
The character was designed with a large crescent moon for a head, sunglasses, and a tuxedo-like appearance. Mac Tonight promoted McDonald's evening business and was associated with a swinging arrangement of the song “Mack the Knife,” which helped give the commercials their lounge-music identity.
Mac Tonight differed from the McDonaldland characters. He was not a hamburger-shaped police officer, town mayor, or food thief; instead, he functioned as a musical advertising figure aimed at encouraging customers to visit McDonald's at night.
The character became especially recognizable through television commercials, although the campaign was later discontinued. The name is sometimes confused with the “I'm Lovin' It” campaign, which began much later and used a different branding concept.