Speed painting I did awhile back.
I wanted the scene to be very serene. As though Godzilla was slowly creeping towards the city early in the morning without giving any warning (aside from the one boater who happened to spot him).
I Didn't want any of the environment disturbed around him during his approach...A "calm before the storm" type of thing.
Since Godzilla is a man made perversion of nature I wanted the mist to play a part in hiding his presence.
Almost as though the forces of nature were somehow aiding him during his approach to the city for payback.
The mist was just a subtle hint to give the impression that Godzilla might not just be a giant radiated lizard or a product of science gone wrong, but there might be some kind of supernatural "diety" type forces at work here.