Near the end of the video, you can see alien-looking creature getting caught up in the output from the ROV thrusters. The video has not been altered and was taken off the East coast of Africa.
This mysterious creature is definitely the closest living creature on earth to being an actual alien.
Marine biologist Bill Austin has suggested it is likely a comb jelly (ctenophore). George Matsumoto, a ctenophore (comb jelly) expert at the Monterey Bay Aquarium and Research institute identified it as a lobate ctenophoreof the Lampocteis genus.
Comb jellies are jellyfish-like creatures, which swim using groups or rows of cilia. Most comb jellies have cilia strips, running along the lengths of their outer bodies.
All comb jellies are predators. Unique among all animals, comb jellies hunt by squirting glue from specially adapted ‘colloblast’ cells onto their prey.