Scientists were left baffled after catching a rare shark that can extend its jaws beyond its mouth - just like the monster from sci-fi hit "Alien."
It seizes its pray with its rapidly extending jaws - which can be used to swallow large fish with one bite.
The glow-in-the-dark beast is so incredibly rare that only a handful have been caught since they were first discovered in 1986.
Taiwan’s Fisheries Research Institute said it had picked up five of the creatures near Donghe Township during a routine survey.
Describing them, it said: “The most obvious feature are the needle-shaped teeth, like snake-like fangs; this is also the origin of viper shark name.”
Because they are so seldom seen, little is known about viper sharks =- but they’re believed to migrate from 300m-400m deep during the day to 150m deep at night.
Of the latest specimens - which were caught at a depth of 350m - four were dead and the living shark was immersed in cool seawater, but died a day later.
The viper shark diet comprises crustaceans and bony fishes, including lanternfishes – perhaps attracted by the predator’s glowing body.
The species was first discovered in 1986 off the coast of Shikoku Island, Japan, by the bottom-trawler, Seiryo-Maru.
Its scientific name Trigonognathus kabeyai honours the fishing vessel’s captain, Hiromichi Kabeya.
This story originally appeared in The Sun.