AGK may refer to:
Agkistrodon contortrix is a species of venomous snake endemic to Eastern North America, a member of the Crotalinae (pit viper) subfamily.
Agkistrodon piscivorus is a venomous snake, a species of pit viper, found in the southeastern United States.
Agkistrodon is a genus of venomous pit vipers found in North America from the United States south to northern Costa Rica.
Common names: Osage Copperhead, Central Copperhead.
Common names: cantil, Mexican cantil, Mexican ground pit viper, Cantil viper, black moccasin, Mexican moccasin, more.
Common names: northern copperhead, copperhead, highland moccasin, more.
Agkistrodon monticola is a taxonomic synonym that may refer to:
Agkonia ovifera is a moth of the Arctiidae family. It was described by Dognin in 1906. It is found in Peru.
Agkistrodon piscivorus conanti, the Florida cottonmouth or green-tailed moccasin, is a venomous pitviper subspecies found in the southeastern United States, and Florida in particular.