It's a bug, for one.
There are many better options for that brain that are better suited, such as a humanoid body, cyborg, or AI, for another.
And for a third, like Heretic stated, you have to hijack an IPCs body. Of which there is literally zero situations I can think of off the top of my head where this would be permittable/ allowed (sans hijack, I suppose.).
I'm going back to sleep now, but I think we should, again, take a step back and not think on this too seriously. It's a bug, and should probably be removed. Mostly all there is to it.