Sir David Attenborough told BBC TV that the yeti, or abominable snowman, could exist and he is "absolutely baffled" by the footprints.
"Very, very convincing footprints have been found," at 19,000-foot elevations, he said. "Nobody goes up to 19,000 feet just to make a joke."The above photograph is from December 1951 and is an alleged footprint of a yeti near Mount Everest.
Attenborough, 82, is known for his coverage of animals and nature for the BBC.
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