In each book of the Beast Quest series, the hero must battle a mythological beast. The beasts in question include a centaur, a dragon, a serpent man, and a flame bird.
Author Adam Blade likes the yeti, apparently.
Of the seven Beast Quest books currently published, THREE of them feature a beast that is yeti in all but name.
And coming up in May 2008, Claw the Giant Monkey is probably a yeti in disguise as well.