Item from remembrance-of-earths-past by
The native sentient species of Trisolaris — a civilization of beings who think in transparent visual flashes, cannot lie, can dehydrate themselves into stacked sheets to survive Chaotic Eras, and have spent four hundred years coming to take Earth.
Trisolarans are the trilogy's central alien — utterly different from humans in their inability to deceive, utterly familiar in their fear of extinction. Their society is honest by biology and ruthless by necessity; the Princeps' decisions are debated in the open because no one can hide their thinking. They learn deception from Mike Evans' bedtime stories and decide, almost immediately, that humans are too dangerous to coexist with. The destruction of their planet by Singer's photoid is the trilogy's quiet middle-act apocalypse — their fleet survives, but their world does not.
Trisolarans communicate by emitting visual light pulses — their thoughts are essentially broadcast. Their physical form is never directly described to humans, who are kept rigorously ignorant; only their VR avatars, robed and faceless, are seen. They can dehydrate into rolled sheets thinner than parchment, then rehydrate when conditions improve.