Shellbacks are a unique type of sea creature that is often a subject of fascination. These marine animals have a hard outer layer that acts as their protective shell. But, there are many other words and phrases that can be used to describe shellbacks. Some common synonyms include turtles, tortoises, terrapins, and shelled creatures. These words are often used interchangeably to refer to any animal with a protective shell on their body. Other terms, such as carapace, plastron, and scute, are more specific and describe the individual parts of a shell. Regardless of which word is used, shellbacks remain a wonder of the natural world.