In fantasy, you have the usual creatures, but you also have the unusual to go right along with it. Creatures that give you the heebie jeebies or a sense of awe. They can be just about anything. I have a book called, "The Encyclopedia of Things That Never Were". Makes for some interesting reading.
The Djinn or Genies ~ Wish granting, smoke-legged beings that can range from evil to good all seem to have their own agenda. Get their bindings off of them no matter the cost. Be careful what you wish for? Absolutely! If you wish for riches, someone close to you will die so you can inherit the wealth. Wish for anything and the Djinn will take it from someone close to you so you may have it. Wish granted.
Bunyips ~ Water monsters with a diet consisting of mainly of women and children. Their cry is a loud, booming roar. Their description varies so much, because people who have seen them never live to tell the tale.
Banniks ~ If your stories have a bath house or anything related to steamy saunas, bring in Bannik-like creatures. Their touch against bare skin is unmistakable. A caress brings good fortune, a scratch bodes ill.
These are just a few. For the life of me, I can't recall any others and I know there are tons of them out there. Tell me some unsual creatures in the comments!