Yongary, Monster From the Deep
대괴수 용가리 (original)
An earthquake from an atomic blast rouses an amphibious colossus, which then attacks South Korea.
Starring Yeong-il Oh, Nam Jeong-im, Lee Soon-jae, Kwang Ho Lee, Cho Kyoung-min, Moon Kang
Watch "Yongary, Monster From the Deep" on Amazon released in 1967. It's a science-fiction and horror movie, and has a rating of 3.8 out of 10 from Imdb which is fairly low for this kind of movie, and is currently only available for purchase or rent.