The phrase "Sea devil" is often used to describe various sea creatures, particularly species of sharks, rays, or even octopuses that are considered to be fierce, cunning or dangerous. However, there are other descriptive terms that could be used to convey similar meanings. For instance, the "Jawsome" or "Apex predator" could be used to describe a shark. A ray could be referred to as a "Stingray" or "Electric ray". An octopus, on the other hand, could be described as a "Mimic octopus" for its ability to camouflage and blend into its surroundings, or "Giant octopus" for its impressive size. These alternatives are more descriptive and colorful compared to the typical "Sea devil".