When Thomas Headland first met the world’s longest snake, he was on the way to the toilet. He was living in the Philippine rainforest with a group of hunter-gatherers called the Agta. On the walk to the outhouse behind his hut, he stumbled across a reticulated python curled up on the trail. “The hairs on the back of my neck stood up and I shouted for help,” he recalls. At his cries, six to seven Agta jumped up from the surrounding bushes… and started laughing. Their new American neighbour had fallen for the old previously-killed-python-on-the-path gag. “I didn’t know what jokers these people were at the time,” says Headland.

Giant snakes frequently attack people in fantasy and science-fiction stories, but