Crenga are thought to be almost entirely extinct, and there was once stories of whole colonies of Crenga living on far-off islands. It is unknown why the Crenga have been brought to the edge of extinction.
They are very tall, with extremely long, multi-jointed limbs and grey skin. Crenga have yellow eyes, high-pitched voices, and androgynous bodies. There have only been 2 Crengarrions shown in the series, Nye and Mantis, but both wear some form of face coverings most of the time - Nye rarely removes its surgeons mask, and Mantis never takes off its gasmask.
They reproduce by becoming intoxicated by alcohol and having pieces fall off. These pieces eventually grow into other Crenga. This process closely resembles fragmentation asexual reproduction, where a new individual being is formed from a piece of the parent.