Kingsnakes, of which there are several species, are not venomous, and as a group they actually prey upon venomous snakes. Some species of king snakes do resemble venomous snakes, but kingsnakes kill their prey using constriction, not venom.
Kingsnakes prey upon a variety of animals, including rodents, but they are known for eating other snakes, including snakes that have very dangerous bites. They are naturally immune to the venom of pit-vipers, one of the major groups of venomous snakes found in the Americas. Kingsnakes will bite humans if they are disturbed, but the bite presents no more danger than that of any other animal. The scarlet kingsnake closely resembles the venomous coral snake, but as with other kingsnakes, it kills by wrapping around and squeezing its prey rather than poisoning it.