The simple fear generated from saying, “Did you hear that?” while you’re sitting out in the middle of the woods isn’t something that can be explained to someone who hasn’t been there.
Any movie with a title like The Werewolf and the Yeti needs to be a movie full of scenes where a werewolf fights a yeti. If the movie doesn’t live up to that title, you’ve ruined humanity’s chances for an awesome movie in which a werewolf fights a yeti
The snow devils appear when the Gamma One team stumbles across some space yetis in a cave. Rod and his crew are taken prisoner by the yetis, who seem primitive despite their cave being decorated nicely. It turns out the decor is courtesy of the head space yeti, who dresses like a terrible superhero and politely explains the entire nefarious plan.