Saw this as a kid. Took so long to get going I am sure I clogged three arteries before the first sign of the blood beast forty minutes into this potboiler taking advantage of the resurgence of "rated G" horror circa late fifties. How this ever got the Criterion treatment I'll never know, but the list here is rife with grade Z potboilers in that genre.
Normally this is the place I complain the movie was cropped, but this flick was filmed to be able to play even to those theaters that hadn't been converted to other than 1:33--it's actually in 1:37.
I give it a pass because of Marshall Thompson.