Grog

Grogs are a sapient species of sessile telepathic life forms from the deserts of Down: a planet orbiting Luyten's Star and originally colonized by Kzinti, before being conquered by Humans.

In their immature stage, they are quadrupedal, non-sapient and remotely controlled by the adults by means of telepathy.

It's been theorized that the Grogs might be the degenerate descendants of the ancient Thrint species.

Biology
Adult Grogs are conical creatures, about five feet in height (~ 1.52 meters) and four feet wide (~ 1.22 meters) at the base. Their bodies are covered in long hair the color of red-tinted sand, with a rounded bald top that makes them look like a caricature of a Franciscan monk. They have two pairs of hairless pink paws which dangle from their bodies without reaching the ground. The lower pair has been compared to a dog's forepaws, while the upper pair has longer, curving digits that look more like fingers. They have neither eyes nor nose. Their faces consist of a lipless wide mouth which contains an elongated prehensile tongue. The mouth curves slightly at the tips, giving off the appearance of a smile.

Despite their comical appearance, adult Grogs are intelligent creatures, with brains more than twice the size of a Human's and powerful telepathic abilities. Compared to Humans, however, Grog brains transmit impulses more slowly. Their psychic abilities are developed to the point that they can control other life forms effortlessly, and use this to attract prey towards themselves, order scavengers to clean up after them and groom their pelts, and control the mating habits of their young. They perceive the world through the senses of other creatures, needing no sense organs of their own.

Life cycle
In their young mobile stage, Grogs are tail-less quadrupeds with forepaws resembling chicken feet. The females are the size of bulldogs, while the males are closer to Chihuahuas. Both are covered in shaggy reddish fur and have eyeless faces and lipless mouths with serrated horseshoe-like cutting surfaces instead of teeth. They emanate a faint odor which has been described as odd but not unpleasant.

Grogs mate in their mobile stage; controlled by the sessile adults. After mating, the female is directed by the adults towards a suitable rock in which she can begin her metamorphosis and shift into her sapient immobile stage. During this transformation, their brains develop, giving them psychic abilities that allow them to control the minds of other creatures. Being able to bring prey towards them, they no longer need to move. Their limbs degenerate and even their spinal cords atrophy.

Culture and society
Despite being descended from the ancient Thrintun, the Grogs seem to share none of their ancestors' hostility, and are mostly friendly creatures, willing to help out Human settlers by doing things such as herding cattle or monitoring animals at zoos in exchange for access to encyclopedic knowledge about the universe.

Appearances

 * "The Handicapped", by Larry Niven (1967)
 * "Grendel", by Larry Niven (1968)
 * Ringworld, by Larry Niven (1970)
 * "One Night at the Draco Tavern", by Larry Niven (1991)
 * Crashlander, by Larry Niven (1994)