A crab or a spider? Closer to a spider—an animal that crawled the earth 400 million years ago, predating many dinosaurs. They are the champions of survival having survived a number of extinction events. Other organisms that share this longevity are the jellyfish and ancient forms of algae.
Planning layout and doing the research is everything that immediately follows your original idea. I feel it's a bit like putting together a 1000 piece jigsaw puzzle. Slowly but surely the graphic takes shape with patience and perseverance. Continually critique yourself and you will likely end up with better artwork.