Monster Brains just featured a great collection of vintage sci-fi book cover art. I have a few favorites from the bunch.

This one definitely warrants a caption contest. What exactly is the facial expression on the giant fish creature as he drains the blood of the young boy? Is he awestruck? Terrified? Aroused?

This enormous, lush-lipped bat seems to have whole forests on its hind quarters, and possibly a castle:

And you have to commend the imagination of this psychedelic, robotic, architectural, ant infested, lupine, space-collage skull…thing: