There are importers and exporters all around the world for reptiles; many come from Africa and South America were reptiles and amphibians are abundant. Well Madagascar for instance has a quota on how many cites animals they can send out like panthers, those get distributed to various importers around the world. Exported animals usually get imported to the U.S. at major ports such as New York city, L.A., Miami etc.. At those ports there are basically a giant warehouses were reptiles come to and operate like a big pet store that sells animals in bulk. Breeders, pet stores etc., can go there and pick animals. Some breeders with import/export licenses can bring there own shipment in (have to get in contact with an exporter who will ship one to them). Some animals come in gravid and breeders hatch/ raise the young making them CH.
-Mike