In appearance they are a physically large and powerful bipedal species with muscular build, rough scaley skin, retractile claws and thick hides, growing up to eight feet tall. Kdatlyno are one of the few sentient races that can physically intimidate an adult Kzin.
They have no eyes, having evolved on a world which instead drove the development of echolocation rather than vision of the visible light portion of the EM spectrum. A large membrane called tympanum makes up most of the head; by making a constant ultrasonic signal, it can sense size, motion, range, temperature of remote objects and their interiors.
There is at least one mention of them being used as elite Imperial Guards for the Kzinti Patriarch, presumably due to both their great strength and their uninvolvement in Kzin imperial court politics.
They are suspicious of outsiders and aloof to alien species and have a strong sense of personal honor and vengeance, comparable to that of the Kzinti.
Migrant Kdatlyno excel in professions pertaining to their sensorium such as medicine or touch-sculpting. The most famous Kdatlyno is Lloobee, a touch-sculptor who works primarily for a human audience.
Grendel (short story), in Neutron Star (New York: Ballantine, 1968, pp. 51-72 ISBN 0-345-29665-6)
- Kdatlyno at the Encyclopedia of Known Space