This is the horrifying moment a king cobra was found on the roadside - locked in fierce death grip with a python.

The two predators clashed in the undergrowth before spilling out in front of passing drivers in Nakhon Si Thammarat, southern Thailand on December 9.

Footage shows how the python wrapped its thick body around and tried to constrict the black king cobra, which then sank its fangs into its opponent's neck.

Onlooker Anoochit Preecha watches as the two reptiles both struggled to exert dominance while they were twisted in the gruesome duel.

He said: ‘One was fighting for its life, and one was satisfying its hunger. I’m lucky to have witnessed such a rare event.’

Pythons kill their prey by strangling them to death, while cobras strike at the base of their target's neck to inject a deadly venom.

On this occasion, the cobra was able to hold out long enough while its deadly venom weakened the python, causing it to lose its grip. It then slowly died before the cobra swallowed it whole.

Some snakes, including pythons and cobras, engage in cannibalism when they clash over food or territory.