The Rock Pool Project in Plymouth says the non-native sea hare looks "alien-like".

It might look like something you'd find in an alien salad, but this bizarre sea slug can actually steal body parts from other organisms and use their powers for itself. "This is an organism that can ...

A mysterious 'alien' creature with a transparent head and 13 legs has been spotted at the bottom of the ocean by a baffled deep-sea diver. The strange animal appeared to sport a large jelly-like ball ...

Some of the most bizarre lifeforms on Earth lurk in the deeper realms of the ocean. There was so little known about one of these creatures that it took 20 years just to figure out what exactly it was.

Beware of blue dragons: Venomous alien-looking creatures wash up on Gulf Coast Sea slugs called "blue dragons" are washing up on Gulf Coast beaches, and officials are warning beachgoers to avoid them.

Sea slugs are one of the world’s most stunning, diverse, and adaptable animals. Not only are sea slugs beautiful to look at, but their methods of survival are unparalleled. While some marine species ...