Instead of filming a puppet of Godzilla in stop-motion, as O'Brien had done for King Kong, Tsuburaya put an actor in a rubber suit and ran the camera at high speed, making Godzilla's movements seem appropriately ponderous when played back. The suit, however, weighed 220 lbs. (100 kg), and the actor inside it lost 20 lbs. (9 kg) in six weeks of shooting.
Buy the book here:
Eiji Tsuburaya: Master of Monsters: Defending the Earth with Ultraman and Godzilla
I flipped through this book recently in a Barnes & Noble and it's just packed with photos like the one above. I worshipped Ultraman as a kid and there's tons of info in there about him. This is going on the Christmas list for sure.