The Manster was a two-headed Japanese monster just slightly pre-dating the giant monster genre that would become associated with Toei productions. Thus, Alex Simmons story begins with a double joke: the play of words involving of course The Ice Man Cometh and the more subtle joke of including a nod to a Japanese classic.
Japan doesn't figure into Mr. Simmons story. Instead, we have a haunted ice cream factory, and a very intriguing design for our fake monster--or manster, if you prefer--by the accomplished Joe Staton and enhanced by sharp inker Horacioi Ottolini. This is indeed very keeping with the formula of Scooby-Doo in that the monsters never looked fake. We knew that they would be unmasked as say "Creepy Uncle Joe!" but the monsters never looked fake. Heroic Age must also be given credit for the cold colors that give off the ghostly glow.
Simmons' story is a treat. It departs cleverly from the formula of fairplay and instead diverts into a detective story that while perplexing stays slickly paced with a rational explanation for the behavior of the culprit.