The Anguilla are a species of oceanic (presumably pelagic), eel-like organisms indigenous to the planet Alluuvia, which is located within the Elrood Sector. Despite their eel-like physiology, they were obviously not eels, and were distinguished from them by long arms ending in powerful hands and webbed fingers (for propelling them through the water) and infrared vision.
Anguilla led a primitive lifestyle of that of nomadic hunters, following the migration paths of schools of the local fish-equivalent species. Leadership was determined through tests of strength, known as the Rites of Conch-tar. They were discovered by the galaxy as a whole - specifically by the Galactic Empire - not long after the Battle of Yavin. A bigoted Imperial Private shot the first Anguilla he saw upon arrival on the planet on sight, and his fellow Imperial soldiers followed suit, leading to a massacre of their people.
In defense against these would-be encroachers, the Anguilla were aided by the Rebel Alliance and led by Anyar in destroying the local mining base run by Imperial Mining, Limited. Anyar then negotiated for Radell Mining Corporation to mine the minerals, which is toxic to Humans, that filled Alluuvia's oceans instead, on the condition the mining was overseen by the Ithorian Iych-thae.