Gamera: The Giant Monster

"Gamera is a good turtle!"

—Toshio, after Gamera has destroyed Tokyo and killed hundreds of thousands of innocent people.

Gamera: The Giant Monster (Giant Monster Gamera, or Daikaiju Gamera) was produced and released in Japan by Daei studios in 1965. The film originally started life as a story about giant rats, but when the rats that were going to be used ended up being unuseable due to fleas and other reasons, the filmmakers retooled the script changed the monster(s) into a giant turtle. The film was shot in black and white, one of the last giant monster movies to be filmed like this, and is one of only two movies to portray Gamera in a villanous manner, with the other one being its immediate sequel, Gamera vs. Barugon. Giant Monster Gamera was directed by Noriaki Yuasa, who also directed the special effects.

For the Mystery Science Theater 3000 episode see here.

Tropes used in Gamera: The Giant Monster include:

Atlantis: The stone tablet that Dr. Hidaka looks at implies that Gamera lived on the lost continent...somehow.
Friend to All Children: Gamera, although this would be ignored in the next film. It's part of why Toshio believes that Gamera is a good turtle who's only lost and confused.
Gentle Giant: Toshio would like to believe this about Gamera, but it's clearly not the case.
Giant Equals Invincible: Since conventional weapons don't work, and the energy of nuclear weapons would only feed Gamera, the only feasible solution is to trap him in a rocket and send him to mars. No, seriously.
Giant Flyer: Gamera. This, and his love of children, is what sets him apart from Godzilla.
Gratuitous English: How do I put this...yes, however, when the actors speak in short sentences, their English is rather good. It's when they speak in really long sentences that things get...iffy.
Intrepid Reporter: Mr. Aoyagi, although he really just wants to be near Kyoko, even going so far as to call her his "Goddess of Luck."
Too Dumb to Live: Toshio certainly counts after getting on a train car heading straight for Gamera, after the monster has already destroyed most of Tokyo.
Turtle Power: Gamera.