Was this sleep paralysis, or just a regular nightmare?

So here's the scenario. I wake up, I'm flat on my back and I can't move except for my head and my eyes, and I can't speak. I'm terrified and sense an evil presence, specifically an evil scientist, somewhere in the room but cannot see him.

This is consistent with what I know about sleep paralysis.

However, I'm not flat on my back in my bed. I'm flat on my back on a patch of perfectly flat swampland, with a grid superimposed upon it, each grid square about two or three feet across. Nearby I can see an alligator watching me. The unseen scientist is operating on me, implanting an egg (resembling one of those plastic dinosaur eggs you sometimes see in natural history museum gift shops) into my chest cavity, to use my body as an incubator for the egg. Somehow I know that this is an alligator egg, and that the alligator nearby is its mother and is very territorial. One wrong move by either me or the scientist, and she'll attack me. The scientist is narrating what he's doing and the reasoning behind it out-loud, in a calm, detached manner. He's speaking in the third person, and his voice is slow, with a slight Southern accent, bearing a very close resemblance to a narrator I remember hearing on an old educational recording, distorted as if being played back on a very old phonograph record, but I know that he's talking in real time.

This feels more like a regular nightmare. However, I'm wondering if its possible that my sleep paralysis-hallucinations were simply much more elaborate than those people normally experience during sleep paralysis. Could the facts that I'm much more aware of my dreams than most, and/or that I knew a good deal about sleep paralysis ahead of time have caused this to happen? What do you think?