The Selenome was a marine-based colonial organism, functioning similarly to a carnivorous coral reef. Although they appeared to be large collections of stones situated on the seabed, Selenomes were actually single entities possessing numerous tentacles lined with dentate suction cups. These tentacles were composed of smaller, symbiotic organisms that worked in conjunction to increase the probability of successful feeding. The Selenome possessed regenerative capabilities and lacked any inherent enemies in nature. Its sole weakness was the absence of food.
A Selenome situated on the planet Vandor-3 served as a training adversary for clone trooper exercises during the period of the Clone Wars, and almost resulted in the death of Alpha-98.