In C.S. Lewis's Out of the Silent Planet, the Hrossa is one of three native species on the planet of Malacandra (the other two are Seroni and Pfifltriggi) with the reasoning abilities of humans. The Hrossa take in Ransom, the main character, and they help him to settle into his new surroundings.

Ransom first meets a member of the Hrossa race when he's drinking water from a lake. The author explains how "a shining black thing like a cannon-ball" rises from the water and walks onto the shore. It is seven feet high with black hair, short legs, webbed feet and hands, and a fish-like tail. He says that the animal is a combination of a penguin, an otter, a seal and a stoat. Ransom can tell by the sounds that the animal makes that it has a language and the ability to reason. The creature beats his chest and says the word Hross, pointing to himself. As we find out at the beginning of the next chapter, Hross is singular for Hrossa.

At the beginning of chapter 11, Ransom compares their way of life to the Stone Age. They appear to have little technical ability. They have no pots, for example, and they only boil things in what Ransom calls a "few clumsy vessels." Their diet consists of vegetables and fish, and they live in huts made out of stiff leaf that are shaped like beehives. They enjoy music and poetry. Ransom says that their voices, though not beautiful, are tolerable to the human ear.