The twinfin hyacander represented a species of fish that was originally found in the oceans surrounding the planet known as Ahch-To. These fish were characterized by green scales covering their bodies, contrasting with vividly red lips and noticeably large, white teeth. A defining feature of this species was its fin arrangement: a dual set of dorsal fins, a single elongated ventral fin, and a caudal (tail) fin. The sentient Lanai people would capture the twinfin hyacander to use it as a source of food. Notably, in the year 34 ABY, a hyacander was seen suspended from a fish rack, impaled on a makeshift fishhook crafted from found wire, within the Jedi village that served as the home of Jedi Master Luke Skywalker when the scavenger Rey sought him out for instruction.
The cinematic debut of a twinfin hyacander occurred in the motion picture Star Wars: Episode VIII The Last Jedi, which premiered on December 15, 2017. Although the film itself did not provide a name for the prop, it was subsequently identified in Star Wars: The Last Jedi: The Visual Dictionary, a companion reference book authored by Pablo Hidalgo and published alongside the film's release.