A Japanese manga artist best known for his "Ge Ge Ge no Kitaro" comics, many of which can be downloaded from this site.
Kley was a German caricaturist, editorial cartoonist and painter. Much of his imagery focused on fantastic scenes depicting humorous and often disturbing imagery, some of which I've posted below. I found the picture above of the giant catterpillar attacking a woman especially creepy.
"Daniel Johnston is a prolific American singer, songwriter and artist. Johnston suffers from bipolar disorder and often writes surreal songs about his hallucinations and mood swings." Quote taken from wikipedia.
This gallery hosts pdf files of issues from "Gore Shriek", a trashy monster horror comic from the 80's. Scattered through some of the issues are creatures like this. Check it out.
This first link is an interesting array of small images of various sea abominations.If we imagine a shark that could raid out upon the land, or a tiger that could take refuge in the sea, we should have a fair suggestion of what a terrible monster a large predatory crab might prove. And, so far as zoological science goes, we must, at least, admit that such a creation is an evolutionary possibility.
Then there are the cuttlefish, the octopus, and other denizens of the deep, any of which might conceivably grow in numbers, and extinguish man. "
Finishing off Pulp week here at Monster Brains, here is a gigantic gallery of sci fi and fantasy pulp covers spanning many decades and dozens of publications. The number of covers they have collected here is really impressive, there must be at least a couple thousand pics to browse through. They have sections for pulp magazines, paperbacks, interior illustrations, and many French language magazine covers. 
This first link has a collection of "classic crime and horror covers", with an array of horrific scenes of monsters, aliens, zombie freaks and other weirdos.
Here is an incredible collection of pulp magazine covers of the horror variety. From Creepy, Eerie, Tales From The Tomb, Nightmare, and many other titles, there is a great selection of horrific and fantastic covers to check out here.
Fletcher Hanks comics are filled with rigidly drawn characters battling bizarre forces with powers that are both Godlike and surreal. The use of primary colors in most of Fletcher's comics only adds to the strange dreamlike atmosphere of the stories.
Another great artist associated with pulp comics, Finlay's intricate linework is comparable to the likes of Gustave Dore or Albrecht Durer. 
