Vampire Fans?

[Infamous as Elle!]

Aww but I've always considered animals to be fuzzy people, they just speak a different language and speak it directly from their hearts.

Although I do like that idea.  I've also always liked the idea that Native Americans sometimes took on the guises of animals.

[Sebastian]

...
I'm debating bringing other fantastical beings in.  On one hand I'm thinking I'm going to have enough on my hands sorting out the world of my vamps and on the other, if there are vamps out there shouldn't other mythical creatures exist?  I don't know, it may be something I work in later if I have enough brain cells.  I also don't want to be ripping off any of my...ahem....favorite authors.
...

In her Women of the Otherworld series Kelley Armstrong first introduced the werewolves, the only supernaturals in book 1. The were's introduction to the larger supernatural society (Vamps, Witches, Half-demons etc.) constitute part of the plot for book 2.
It's a viable technique, and helps avoid introducing too much information to remember at any one time. 

[Chiroptera]

There's also the option of just making passing mention of other supernatural beings existing - ie. other characters briefly mentioning it in conversation.  That way you don't have to go too in depth at first and heap up too much on the reader and you've also laid some groundwork; if your original story idea becomes more than one book you've got some background to use to introduce other characters.

[Infamous as Elle!]

That seems like a good route.  I may mention things here or there but make it so that it stands on it's own, easily contained in case there aren't other books.

[the neurovore of Zur-En-Aargh]

That seems like a good route.  I may mention things here or there but make it so that it stands on it's own, easily contained in case there aren't other books.

I think the most important question here is, how big is your story compared to your world ? Do you want the story to feel like it deals with all the major stuff that's going on, that everything it introduces is plot-important and will be resolved, or do you want it to feel like a slice through a much larger universe with many more stories and things going on outside the scope of the one you are telling right now ?

There's no right answer to this one; there are great stories that take either approach.  But if you're aiming for the former, you probably don't want to introduce that much at a world-building level that is not entwined with that particular story; if you're aiming for the latter feel, the more depth and density that is in there outside of what's important to your actual plot, the better.

[Infamous as Elle!]

Well, I'd like to make it several stories but I think it'll really depend on my persistance.