The Detroit Zoo has a king brown snake and says it is the only one in North America. Someone with a desire to remove himself from the gene pool was keeping it as a pet even though at the time there was no antivenin for its bite in the western hemisphere. The authorities found out about it and seized it. The keeper I talked to regarding it said the guy had protested that he was being really careful with it. We have a large amphibian exhibit and I'd guess we must have a couple of species not on exhibit anywhere else, but I don't know for sure.