Blink and you’ll miss it. Towards the end, when the Ecto Containment System is shut down and the ghosts escape, keep and eye out for the billboard for Stay-Puft Marshmallows. The Stay-Puft Marshmallow Man is unmissable, heralding the form of the Destructor.
“Sub-creatures! Gozer the Gozerian, Gozer the Destructor, Volguus Zildrohar, the Traveler has come! Choose and perish!” – Gozer, Ghostbusters, 1984.