A sea spider, also known as a pycnogonid, is a marine arthropod with a peculiar appearance. While the name "sea spider" is commonly used, there are a few synonyms that may be used to refer to these fascinating creatures. One alternative term is "arthropodan," which refers to any animals with jointed legs, including insects, spiders, and crustaceans. Another term is "sea tick," which is a reference to the small size of these creatures and their habit of clinging to rocks and other surfaces. Additionally, some scientists refer to them as "coral grasshoppers" due to their long and skinny legs. Regardless of the name used, sea spiders are a unique and intriguing part of the marine ecosystem.