That character isn’t unlike the Stay-Puft Marshmallow Man to begin with, being giant and white, which makes the inclusion of the actual Marshmallow Man all the more confusing.
We know Stay-Puft won’t be the film’s primary villain, that honor goes to a character named Rowan who, by the end, becomes a giant version of the familiar Ghostbusters logo (but with a bowtie).
We have to say this about the new Ghostbusters, it has not failed to keep us on our toes.
We’re also assuming that this one is simply a ghost marshmallow and not the embodiment of an ancient Sumerian god.