Alien (Bermuda Tentacles)

This creature is actually a gigantic biomechanical outpost which can operate in air, water and presumably space. Its origins are firmly established as extraterrestrial, but nothing is known about the race that built it. It was discovered in the Atlantic Ocean, on Earth, and over several decades it has been responsible for the disappearances of numerous ships and aircraft in the area known as the Bermuda Triangle.

Biology
The alien being is equipped with bioluminescent tentacles which can extend for over 7000 meters and are used to probe its surroundings as well as means of attack. It sinks and collects vessels to feed on their power sources, as it can both consume and discharge electrical energy. It's also capable of fast regeneration, making it considerably hard to def