The Stay Puft Marshmallow Man vs. The Busters- in Ghostbusters (1984)
All they had to do was empty their minds, but of course Dan Aykroyd messed it all up. When the 112,6 feet tall Stay Puft Marshmallow Man arrives to bring an end to mankind, the first thing he does is approach the Ghostbusters.
Mr. Stay Puft himself was a complicated suit, featuring a cable operated head with a few limited facial expressions. Some shots of him walking down the street was accomplished by shooting the suit against blue screen and inserting him into footage of real streets. Other shots, however, featured the suit in an appropriately sized miniature environment, such as this shot, where he's walking past Central Park.
The street and the park is a forced perspective set, built by model maker extraordinaire Mark Stetson and his crew, at the EEG effect facility. Included in the model was a fire hydrant, rigged to spray sand, which looked like water at chosen scale and shooting speed (72 fps). The model also had to accommodate the cables to control the Stay Puft suit, which ran down a slit in the middle, down to the four puppeteers required for the job.
The scale of the setup (1:18) proved to be a nightmare, since no model cars were made in that scale. When the effect team finally did find one such car - a model of a New York police cruiser - they had to raid the entire stock from every Toys 'R Us in the vicinity and convert the models to represent other types of cars. A few of the cars were radio controlled, so they could perform complicated moves, the rest were simply pulled on wires.
Completing the illusion was a blue screen shot of the Ghostbusters, done on the rooftop set, and a matte painting of the buildings in the middle of the frame, to tie the two together.
In light of everything else that happens in Ghostbusters, this is a rather inconspicuous shot, but that doesn't make it any less magical.