I have no idea what to make of Shipton's famous photograph of a yeti track. It looks like a real, albeit strange, footprint, but with no expertise on the subject I defer to people who know what they're talking about, like Darren Naish. I was reading an entry in his blog "Tetrapod Zoology" in which he discusses the print, and was struck by a particular point.
"As several of you noted previously in the comments, the track is made unrealistic by the strange, irregular depressions that occur at the left and right edges, and particularly at the heel. These cannot be reconciled with real structures that occur on a primate's foot, and they can't be taken as evidence for melting because the very sharp edges of the track must mean that - as Shipton and Ward noted - it was fresh and undistorted by sublimation. " http://scienceblogs.com/tetrapodzoology/2008/06/most_famous_yeti_track.php
What if we assume, for the sake of argument, that it really is a yeti track? Could those irregular depressions be nothing more than the results of snow balling up on the creature's hair? My Cairn terrier, Possum, disliked winter because after a short frolic her fur became caked with snow and the sensation made her uncomfortable. Could yetis have the same problem?
The Shipton photograph.
A Cairn terrier in the snow (from http://www.highlandpix.co.uk/about.htm)
And, for no particular reason, a Japanese macaque.