The X Files has, in name at least, spawned The X Creatures (Pearl, 8pm), a new series exploring the sort of mysterious mythological animals that might interest agents Mulder and Scully.
This, though, is pure documentary, with biologist, writer and presenter Chris Packham exploring the myths and evidence for the continued existence of large apemen, aquatic monsters and extinct tigers, and then testing this against the essential rules of biology.
This measured series from the BBC starts with one of the most famous X Creatures, the 'abominable snowman' or yeti, in Yeti, Myths And Men, and the creature's place in Sherpa history and culture. But do not be disappointed: Packham is not so unrealistic as to set out across the Himalayas, with film crew in tow, to try to film one of these creatures. Instead, he uses dramatic reconstructions to recall sightings and his own detective work to assess the chance of its existence.
He knocks one myth firmly on the head: that such an elusive creature can live solely above the snow-line. Of course, an ape would need food and shelter from the forests of Nepal and Tibet for its survival. As for those large footprints, Packham shows how small prints expand when they melt and refreeze in the snow.
Packham is not totally dismissive of the existence of an X Creature ape, given the strong fossil record of Asian apes and that the yeti could once have lived alongside man. But the programme puts forward much stronger evidence for 'orang pendek', or the 'short man', believed by many to live in the forest of Kerinchi Seblat in Sumatra and the continued subject of scientific investigation.
Packham also provides some clues as to why we are so fascinated by such ape creatures. The four great apes known to exist are the orangutans, chimpanzees, gorillas and humans, and we share 99 per cent of our genes with the other three. It is no wonder that a more human-like ape, caught in the time-warp of evolution, should be even more interesting.