Here's a nice, long portrait of the titular character in "The Beast From 20,000 Fathoms":
I finally filled that gap in my Harryhausen knowledge a few nights ago. As usual, the animation is outstanding, the creature has a lot of personality and is the reason why you should watch the film, and the humans range from "less boring than the others" to "insufferable" and you have to sit through a lot of their BS to get to awesome monster shenanigans.
I'm instead going to recommend the terrific Netflix streaming documentary, "Ray Harryhausen: Special Effects Titan". None of us will ever be as awesome as him.