The Giant Claw (1957)

Starring Jeff Morrow, Mara Corday, Morris Ankrum, Louis Merrill, Edgar Barrier
Directed by Fred F. Sears
(actor & director credits courtesy IMDB.com)

Attacks by a gigantic bird creature from outer space stymie the military who have no defense against it, but an electronics engineer who was first to sight the creature has a plan that might work.

This picture has been long reviled for its key special effect, a puppet mockup of the creature dependent on wires to make it move, which to be fair just doesn't come off very well, and has encouraged laughter from many audience members.  I still love the film, and the creature, who is quite fearsome in extreme closeup, and admittedly less effective in longer shots, as it's certainly unique among movie monsters.  Samuel Newman & Paul Gangelin's screenplay has lofty science fiction ideas to express, and the cast are completely earnest and serious in their roles, with no evidence of anyone trying to ham it up, other than perhaps Louis Merrill's French-Canadian stereotype.  I won't say that Morrow, Corday, Ankrum, and Robert Shayne bring credibility to the film with their performances- that's probably beyond their abilities, but they give sincere portrayals that don't embarrass themselves, even if the movie may have later embarrassed them.  The film needs better effects, and probably makes too much use of military stock footage, but I remain charmed by it.