This is why you should read Neil Gaiman's blog.

I mean, there are no Neptunian Brain Parasites. And if there were, what would one want with me? What you see in the photo is definitely not a parasitic alien brain-slug. No. Why would you possibly think that? Here, come into this small room with me while I press my hand against the back of your neck... See? Now we are united as one in the slug overmind. Is it not wonderful?