The bizarre-looking creature, which is new to science, was filmed 8,145m beneath the waves, beating the previous depth record by nearly 500m.
Several other new species of fish were also caught on camera, as well as huge crustaceans called supergiants.
The animals were discovered during an international expedition to the Mariana Trench, which lies almost 11km down in the Pacific Ocean.
The 30-day voyage took place from the Schmidt Ocean Institute’s research vessel, Falkor, and is the most comprehensive survey of world’s deepest place ever undertaken.
The Hadal Ecosystem Studies (Hades) team deployed unmanned landers more than 90 times to depths that ranged between 5,000m and 10,600m. They studied both steep walls of the undersea canyon.
Dr Jeff Drazen, co-chief scientist from the University of Hawaii, US, said: “Many studies have rushed to the bottom of the trench, but from an ecological view that is very limiting.
“It’s like trying to understand a mountain ecosystem by only looking at its summit.”
The University of Aberdeen’s Hadal Lander – the UK’s deepest diving vehicle – recorded more than 100 hours of deep-sea footage.