I'm not sure if this was used as a lobby card, window card, or theater handout. The paper is glossy and thin and there's a space below the image to add theater information. Window cards have the space, but usually it's larger, positioned at the top, and the card's paper stock would be thick and rigid. However it was used, you can't beat robots and monsters doing a smackdown with Godzilla.
Okay, so what if my buddy Steven and me pinned pillowcases to our backs and played George Reeves' Superman when we were kids? We didn't jump off of tall buildings, but we did bound around a lot on the porch steps. My mom drew the line when I embellished my pillowcase with the Superman insignia. Not even Lex Luthor was that mean. Then Adam West's Batman hit television and off I went again, but this time I had a plastic, store-bought, Caped Crusader cape. By then my buddy had moved away, but Batman was a loner anyway, so I did okay.
Captain Clegg (titled Night Creatures for the American market) is one of the lesser know Hammer movies. With Peter Cushing, Oliver Reed, Michael Ripper, and other very good actors, it's an engaging yarn of costume intrigue. The spectral image of the skeleton riders impressed a great deal--I was in the single digits at the time--when I first watched this movie on television. (You can see the Mexican lobby card here.)
Here's the big movie herald for Gorgo, "The Greatest Motion Picture Ever Produced!" "Picture of a million amazing thrills!" "Like Nothing You've Ever Seen Before!" This tabloid-sized herald was offered in 1 or 2 colors, blank or with the theater's info. See the pressbook here.
Here's the Mexican lobby card for Invasores De Marte, one of the most frightening, for kids, of all the 1950s science fiction movies. Striking in its simplicity and the skillfully handled budget-art design, who can forget the images of people being swallowed by the sand accompanied by that unearthly sound, or those tall, gawky, fuzzy-clad aliens and their tentacled leader in the glass bowl? And you like ray guns? Well, that's a ray gun! Invaders from Mars is still a film--with its paranoia and mind-control themes even more relevant today--not to be missed.
I don't recall where I picked this up, but that's par for the course with a lot of stuff in my closet. Although in Spanish, you can see it contains the radio spots and other promotional information for Hammer's The Evil of Frankenstein. Of interest is the Universal Pictures Corp de Mexico in the top left corner.