Community Dragon, or cdragon for short, is a massive collection of community-generated files to augment the data in ddragon.
If you can’t find what you’re looking for in ddragon, look in cdragon. This is a useful link to start at. If you can’t find what you’re looking for because there’s so many files and folders to go through, ask on Discord for help.
One commonly sought-after set of images are the rune stat images, which can be found here.