Outsider (Known Space)

Outsiders are a mysterious spacefaring species which travel through the galaxy in slower-than-light ships, following starseeds in their migrations for unknown reasons and operating as information brokers.

Biology
Outsiders look similar to a black cat-o'-nine-tails with a thick oversized handle. The "handle" contains the Outsider's brain and sensory organs, while the long prehensile "tails" are used to manipulate tools. Their bodies are extremely fragile, with no skeletal system. Their metabolism is based on superfluid helium. Their homeworld is unknown, but they are known to inhabit small, cold, airless worlds such as Neptune's moon Nereid, and travel through the galaxy in large, non-pressurized ships with no hyperdrive. Exposure to Earth gravity would be fatal to them. Even under the gravitational pull of Luna, an Outsider would be dead in less than an hour.

Outsiders are believed to have evolved from plant-like organisms billions of years ago, in an unknown small moon close to the galactic core. They feed by basking in starlight while keeping their "tails" in the shadow, so that the difference in temperature between the "handle" and the "tails" creates a current. They get all nutrients they need from the soil.

Culture and society
Outsider ships continually follow starseeds, which migrate from the galactic core to the rim and back. The reason for this behaviour is not known. They are the most technologically advanced civilization known, even though they prefer to travel slower-than-light, without hyperdrive.

Outsiders have information about the entire galaxy and are willing to trade it. According to Beowulf Shaeffer, that is the only trade they engage in. They are an honorable and trustworthy species, but doing business with them is risky because it's impossible to know what kind of information they'll sell. Another difficult aspect is that they don't bargain and their prices are not open for negotiation.

Appearances

 * "Neutron Star", by Larry Niven (1966)
 * "At the Core", by Larry Niven (1966)
 * "The Soft Weapon", by Larry Niven (1967)
 * "Flatlander", by Larry Niven (1967)
 * "The Handicapped", by Larry Niven (1967)
 * Ringworld, by Larry Niven (1970)
 * "The Borderland of Sol", by Larry Niven (1975)