Is there a difference between believing in a god as a real entity and believing in a god as a fantastical being?

For example: I'm an atheist, and yet I believe Raptor Jesus went extinct for my sins over 65,000,000 years ago. Can I really say, then, that I'm an atheist?

You mean there is only a small gap between a theist and atheist?

Atheism equals no belief in the supernatural. If you believe in ghosts or fairies or Raptor Jesus then you're not technically an atheist. That doesn't necessarily make you a theist though. You can say, "There is no god, but I can tell the future with tarot cards" and that's not any less valid than any other crackpot theology. I've decided to label myself a devout agnostic. I'm not just waffling on choosing a religion here, people. I have found my spiritual niche in agnosticism. I can wake up one day and go for a walk and decide that I feel the presence of god and he's totally real, and then get home and shrug it off and figure god is an invention of man, and at no point do I feel conflicted. I believe in whatever I believe at any given time, and I have no issue changing those beliefs. The only belief I won't bend on is that if there is an all-knowing god waiting to judge me after death, he doesn't give a shit what religion I am or even if I believe in him.

Or perhaps you're an inactive paleontologist. Or just a Jack or cultural Paleontologist.

...in the sense that everyone has a superego aspect to their psyche which acts as a conscience, gives rise to feelings of guilt or other existential emotions, etc. It is this aspect, not one's Ground of Being, that people commonly project into the heavens as the "God" they should harmonize their egos with. Removing that projection doesn't remove this aspect of one's subconscious.

...I'm quitting life right now.

Just sayin'

Since god doesn't give a shit about me I'm going to treat god the same way.