Hundreds of Qantas passengers were delayed for a day after a 20cm snake was found in the doorwell of the plane.
370 passengers were forced to spend the night in a hotel after the non-venomous Mandarin rat snake was discovered.
There was concern more snakes would be found on the Japan-bound Qantas flight from Sydney, Australia.
The snake was taken to quarantine and euthanised "as exotic reptiles of this kind can harbour pests and diseases not present in Australia", a spokeswoman told Guardian Australia.
The snake is an Asian species which feasts on small rodents and is usually active at dawn and dusk.
A replacement craft was organised while the original plane was fumigated.
Earlier this year a three metre python clung to the wing of a Qantas flight from the northeast coast city of Cairns to Papua New Guinea in January.
It was found frozen to the wing when the plane landed.
