Most of them are the author 's imagination of what the Necronomicon would be like if it were real , but a few claim to be the actual Necronomicon . The most famous case of a `` real '' Necronomicon is the `` Simon '' Necronomicon , which a young man who uses the pen name ( a fake name used by authors ) Simon claimed to have discovered in the early 1970 's . It was later dubbed the `` Simon Necronomicon '' .