Maccadam was known as one of the oldest Cybertronians alive, his oil house having operated through the Golden Age. For his own reasons, he chose to conceal his identity from his patrons and others; it was rumored that he was one of the staff, but no one knew that he was in fact the piano player. He kept his oil house open during the Great War, making it something of a neutral place where both Autobots and Decepticons could mingle and relax without resorting to violence. However, when the majority of the Autobots departed Cybertron, he refused to continue doing open business with the Decepticons and closed down.
Maccadam soon found business as Ultra Magnus' spymaster in Iacon, where he used his beverage supplies and his various talents to wheedle information out of Decepticons. He would eventually be called upon to help Magnus and the Wreckers locate the missing Alpha Trion, who had been abducted by Shockwave. After sheltering the Wreckers for a time and getting them the information they needed-and being recognized by Wheeljack-the oil house was attacked by Decepticon security forces under Ratbat, but Maccadam got the Wreckers out safely. He eventually made his way back to the oil house, where he was confident he could continue hiding given the Decepticons' need to recover from the Sharkticon invasion.
Maccadam is described as a small but stocky Cybertronian with purple and gold armor and a short goatee.
- Maccadam has been featured in several Transformers series, with little variation between versions. Fans have often speculated that, due to his age and mysterious nature, he might be a member of the Thirteen. Fun Publications made a possible nod to this fact by featuring Alchemist Prime in their Another Light story with a design similar to the one used for Maccadam.