The Family Macruridae, commonly known as rattails, is a group of deep-sea fish found worldwide. These fish are characterized by their long, tapering tails and large heads. While the term "rattails" is commonly used to describe these fish, there are several synonyms that can also be used. These include the Macrouridae, Grenadiers, Whiptails, and Deep-Sea Grenadiers. Despite their somewhat ominous appearance, these fish are an important source of food for many marine animals and are often caught by commercial fisheries. Their deep-sea habitat also makes them an interesting study subject for scientists.