Well, it depends on a couple things.
Where do fantasy and sci-fi separate anyway?
For an example I use the transformers.
Now, they are clearly mechanical in nature so they fit in with sci-fi right? Well, there's this snag here that, in most of the comics and a lot of the animated versions they are divine in origin.
Now here's another thing. We're probably all more familiar with this one.
The force. Now, as we all know it's arcane in nature, but, no matter how much the audience dislikes this fact, it is biological in origin.
Now, here's a third one: Dragons. Now, they feature most prominently in fantasy fiction, but they are usually biological in both nature and origin. This leaves them as Sci-fi creatures.
So really, it all depends on whether you think either of the first two is Sci-fi or if they both qualify as fantasy.