Native to the planet Vodran, the dianoga are cephalopods that can grow up to nine meters in length. Using their long tentacles and eyestalk, they scavenge food from bodies of water, sewers, or even trash compactors. While they feast, small amounts of food are torn apart with their sharp mandibles and fangs. During digestion, the food can be taken into areas under the skin and used to alter the tone to that of their current surroundings, acting as a kind of camouflage.

When a dianoga reproduces asexually, the larvae are microscopic in size. As they grow, baby dianoga are not very bothersome and have even been known to be beneficial for waste management. These infants stow away in starship water supplies, are carried across the galaxy, and end up in local sewer and trash compactor systems. They consume biological matter that is present in various liquid environments and leave behind raw materials to be salvaged.

Full-grown dianogas are much more dangerous. Starving adults are known to emerge from sewers, attacking the weak and unwary. These attacks are stimulated by a lack of nourishment, which leaves the dianoga semi-transparent. Furthermore, dianoga populations can grow beyond control when left unmonitored. Infestations are difficult to eradicate, as the population will re-establish if even one larva is left behind.