Thai customs officials have seized 600 deadly cobras after stopping a vehicle at a checkpoint in a central region of the country.
The reptiles came from Malaysia and were being shipped through Thailand for use in traditional medicine or for food in another country, according to customs officials.
They were apparently destined for Laos.
The cobras were packed into mesh bags inside around 100 plastic baskets and put inside a truck for the long slow journey up from Malaysia. Some of them died on the way.
Working on a tip-off, the authorities set up a specialist X-ray checkpoint in Pranburi, about 230km south of Bangkok, to seize the shipment of venomous animals.
The driver of the vehicle was arrested and the snakes were put into the care of Thailand's Department of National Parks and Wildlife and Plant Conservation.
"It's a lot (of snakes)," said the head of Thai customs, Benja Louichareon.
"The Bureau of Investigation and Suppression have been tracking this case for a year," she added.
Thailand is a major transit country for wildlife trafficking and this seizure follows that of 4,300 cobras in May. Tigers and pangolins are also among recent finds by police.
Officials estimate that the haul was worth around 500,000 baht (£10,500) to the smugglers.
The snakes that survived the ordeal will be released into the wild.