Salaxalan

Salaxalans are a sapient alien species which lived over four billion years ago on the planet Salaxala, located in the Pleiades star cluster.

Biology
Not much is known about the Salaxalans' appearance, except that they have crenellated purple skin, at least two mouths and noses, a single eye and multiple legs.

It's possible that they might have 17, 19 or 23 legs, as they consider these prime numbers to be more "normal" than 2, although they ultimately decided to build robots with two legs rather than 17, 19, or 23, both to save costs and make horse-riding more practical.

It's been claimed that if a Salaxalan was shot, they would be "back next week for another episode", suggesting that they might be very durable and/or capable of regenerating.

Culture and society
Their technological achievements include interstellar spaceships and the Electric Monk, which is a humanlike android whose purpose is to believe in things so that its creators wouldn't need to have faith themselves.

Appearances

 * Dirk Gently's Holistic Detective Agency, by Douglas Adams (1987)