Most of the Godzilla movies used a guy in a very heavy and hot latex suit. The original even had a bamboo structure underneath. Close ups of the feet crushing buildings were the man just wearing the legs of the suit held up by suspenders as he had keeled over from heat exhaustion of the full suit. Willis O'Brien had done the stop motion animation for the 1933 King Kong movie. From there, Ray Harryhausen picked up his craft doing several stop motion pictures such as Jason And The Argonauts, Clash Of The Titans, It Came From Beneath The Sea, The Valley Of Gwangi and many more.