A Large Quantity of Tiny Plastic Dinosaurs

Buy these by the tub, not by the individual figurine. The applications are endless.

Quality is key, but not too much quality: you want them to be painted and clearly readable as this or that particular dinosaur. Conversely, a few creatures that are not dinosaurs mixed in (a not-to-scale crocodile or something that was clearly molded to be a dragon) will improve the overall experience.