Mac Tonight was the McDonald's advertising mascot associated with “Mack the Knife.”
The character was introduced in 1986 as part of a campaign designed to make McDonald's more appealing during evening hours. His crescent-moon head, dark sunglasses, formal clothing, and lounge-singer performance gave the commercials a style distinct from the colorful McDonaldland advertisements.
The commercials used a rewritten version of “Mack the Knife,” a song made famous in popular culture by performers including Bobby Darin. Mac Tonight's association with that melody became the central creative device of the campaign.
Mac Tonight should not be confused with Ronald McDonald, who was the company's principal long-running mascot, or with the Hamburglar, who belonged to McDonaldland. Mac Tonight was a campaign-specific character strongly tied to nighttime positioning.