The BaAka pygmies of the Congo have lived in the area for many thousands of years and are the supreme naturalists and hunters of the rainforest. They have a name, and a use, for every species of plant and animal in the forest. They talk of a huge creature they call Mokele Mbembe which lives in the swampy forests of the Ndoki, one of Africa's last great wildernesses. They say it is large and aggressive, with a single huge horn, and it sleeps on a bed made of elephants' tusks. It sounds like a myth, but with all their knowledge, why would they invent a mythical beast?