Scrambler

Biology
The species looks similar to starfish, and they constantly move their arms in order to circulate fluid, which gives them the name. They are covered in hundreds of eyes which can focus and adjust independently, acting as a single visual array that gives them excellent vision. They do not have any genome and instead the shape of their body emerges from complex interactions between the cells, and the body seems to be 'at war' with itself. To reproduce, they use a form of budding. Scramblers do not require oxygen, as they are born with a store of energy, but require strong magnetic fields or else become sick and die.

Intelligence
When a dead body is examined by the crew's biologist, it is first thought that the Scramblers are 'dumb as a stick', because most of their nervous system seemed to be dedicated to controlling their many eyes and their limbs. When the aliens are tortured to find the true extent of their abilities, they solve the hardest problems the crew can give them easily. They show sufficient intelligence to discover and exploit a flaw in human vision to appear invisible, hiding between eye movements, a feat which also requires extremely acute senses and fast reflexes.

The crew later discover that Scramblers are not truly sentient, as they have difficulty solving a linguistic problem involving self-awareness. Blindsight is a mental disorder where somebody believes that they are blind and does not experience visual sensations, but can still use their sight to move around and perform tasks. Scramblers have blindsight over all of their senses, and do not have conscious sensation. The narrator says that this is superior to conscious thought, as sentience is an 'evolutionary flaw', interfering with quicker, more effective subconscious processes. He refers to creative insights that come from dreams, and musicians who are told not to focus on their actions, as examples. As such, the Scramblers, according to the narrator, show that the very thing that makes humans unique is a crippling flaw that will make the species extinct in the end.