The 31-year-old Thai woman, who has not been named, was arrested on Sunday night after the tiger was spotted by X-ray staff in overweight luggage destined for the cargo hold.
An official from the Wild Fauna and Flora Protection Division said the cub was drugged and placed in the bag with the toys -- apparently to make it appear as if it was a stuffed animal.
"He was very calm, half asleep and half awake when we rescued him," he said.
The cub was found at Thailand's Suvarnabhumi Airport and has since been sent to a rescue centre.
It is not yet known whether the animal was wild or had been bred in captivity.
The woman, who admitted carrying the tiger, according to officials, faces four years in prison, a 40,000-baht (USD 1,280) fine or both for possessing and smuggling an endangered animal.
Manop Lauprasert, of the ASEAN Wildlife Enforcement Network applauded the successful operation.
"We are all very happy to have saved this tiger cub from entering the illegal trade," he said.
