It clearly has unusual adaptations to its harsh environment. It evolved from the deep sea fish that gradually rose to the surface. Some of them then crawled onto land and became amphibians, reptiles, etc. This is a decendent of one of those fish which did not do that, but continued to swim upwards, despite the obvious problems of a lack of water. In order to succeed at this, they developed extra-large fins on the sides of their heads to help in their balance and movement. In the photograph, you can see these two specialised fins, which operate a bit like the pedals on a bicycle. The left one is moving forwards, whilst the right one is moving backwards. This permits rotation of the fish's head, which is also facilitated by a very unusual item of fish anatomy, namely a neck.
Often these creatures find themselves fully out of the water, which they have learnt to survive. However, they are still clearly fish, as can be determined from the curious noises they make which are clearly meant to be heard underwater.
Genus: Lakus
Species: Fishicus
Subspecies: Mintsaucium
Fish that will try and hide
A Clown or Anemone fish
A Goby fish and spot the Alpheid shrimp
A Parrotfish in an odour control sleeping back
A Coral trout with a friendly Wrasse
A spiny Pufferfish defending itself
Well - not fish - exactly...but