This turtle surely makes you think of Godzilla, but know that it is called Gamera. Basically two different films were released, the first for children and the second for adults. Depending on where it comes from, it does not quite have the same origin. In the first version she was awakened by nuclear tests, while in the second, it is a biological weapon.
Here is the complete range of merchandising products, figures and goodies for Gamera.