If you are looking for free, legal PDFs, your best bet is the "Convention Books" published by origami associations. These books often contain diagrams from the world's top folders.
Because these models are difficult to diagram, most are found in published books. However, several legitimate resources offer complex diagrams for download: complex origami pdf
The model shuddered. A crease popped—a sound like a gunshot. The jaw unhinged. The paper wasn't paper anymore; it was a membrane, a skin. It began to inhale, sucking the air out of the room. The stack of failed prototypes on his desk began to slide toward the model's maw. If you are looking for free, legal PDFs,