Class Nuda is a term used in the scientific world to refer to a group of marine animals that lack any protective covering or shell. These creatures are commonly known as naked sea slugs. There are various synonyms that can be used to describe Class Nuda, such as Nudibranchia, which is derived from Latin meaning naked gills. Other terms include sea slugs, sea hares, and opisthobranchs. While they may not have any protective shells, these creatures come in a variety of vibrant colors and intricate patterns. These synonyms are helpful in describing this unique group of marine animals to a broader audience.