U.S. Customs and Border Protection agents received a slithery surprise when they checked a mail container at Kennedy International Airport.

The agency said Tuesday that officials seized five live king cobras and three geckos during an inspection at the airport mail facility on June 29. Agents first discovered the dangerous contents of the package in an X-ray scan.

The reptiles were sent in a container from Hong Kong.

The agency's New York Field Operations Office said the seizure shows the wide-ranging responsibility of the agency.

The reptiles have been sent to the U.S. Fish and Wildlife Service.

King cobras are the world's largest venomous snakes, growing up to nearly 19 feet. (5.8 meters)