Perverse Space Brains live in the space between the world and the Moon.
They look like oversized human brains, including a brain stem, which of course connects to nothing. They have two red and glowing eyes which float in front of their brain/bodies. The eyes have the same size and relative position to the brain as a human's eyes do to their brain. No nerves connect eye and brain.
The 'lizard brain', which in a human governs the animal-like instincts, appears to be separated from the Perverse Space Brain, but to still sleep within it. When threatened the Perverse Space Brain will cause this part to awake and exit it, fighting to protect its 'parent'. This separated part is called a Laser Hound, as it resembles a dog or wolf, and can emit beams of scorching light from its eyes.
The appelation 'perverse' refers to their inhuman thought processes, not to any unusual lusts. Indeed they seem to have no understanding of "this human emotion you call...love." During certain periods the Brain enters a hibernation-like sleep, while the Laser Hound goes forth to seek a mate. Once the new Brain is born the parents separate, returning to their host Brains.