A team of UK dragon-hunters is on an expedition in The Gambia to track down a mysterious creature known locally as the "Ninki-nanka".
Believed to live in swamps, the ninki-nanka appears in the folklore of many parts of West Africa. It is described as having a horse-like face, a long body with mirror-like scales and a crest of skin on its head. Team leader Richard Freeman told the BBC, evidence so far was sketchy as most people died soon after seeing it.
Second-hand accounts varied wildly from it looking like a crocodile or a snake to having wings and spitting fire, he said.
A park ranger from the Kiang West National Park who lived to tell the tale of his encounter three years ago described an immense animal 50 metres long by one metre wide that he watched for more than an hour before being taken ill.
He put down his survival down to a herbal potion given to him by an Islamic holy man, Mr Freeman said.