'Cloakfish' form a group of Furahan aquatic animals that propel themselves with the help of four undulating ribbons, attached to a central spine (the 'dagger'). Each ribbon moves on its own, helping to propel the animal. Phase differences among the four cloaks give rise to a variety of different gaits.

Note that cloakfish are obviously not truly 'fish'. On Earth,'the word 'fish' is used by biologists in a precise sense, but by others, gastronomists in particular, mostly to indicate a marine edible, usualy an edible one. A crayfish is just one example. On Furaha the situation is unfortunately similar: citizen-scientists reserve the word 'fish' for the clades 'Fish I' to 'Fish VI', that have nothing to do with cloakfish. But the word 'cloakfish' is too well known for it to ever disappear from the language.

There are several blog posts on cloakfish:
- Early cloakfish sketches
- Another cloakfish animation
- About depicting cloakfish
- Cloakfish evolution and design
- A better cloakfish animation

The 'reef perch' sports a greatly enlarged and laterally flattened central spine, which now has a larger mass than the body proper. The upper and lower cloaks provide almost all of the propulsive force. It pushes rather than pulls itself through the water. The lateral cloaks can provide propulsive force, but mostly aid in stability. These species are remarkably agile, but their basic body plan is not well suited for sustained swimming or high speeds. The ecological niches requiring these abilities are usually filled by Fishes VI. Cloakfish tend to live in reefs, where agility is more important than speed.

Quite a few cloakfish are bioluminescent. In fact, as on Earth bioluminescence is very common in marine animals. This particular species, the common cloakfish, is in shape very close to the general ancestral body plan of the cloakfish pattern. It is covered in small dots giving off a greenish light, the purpose of which is not at all clear.