Eel-shaped is a commonly used term to describe something that has a long, slender and curved shape resembling an eel. However, there are several synonyms that can be used to describe the same shape, such as serpentine, sinuous, wavy, undulating, curvaceous, meandering, and coiling. These words are often used to describe objects like rivers, roads, and some animals that curve and twist in their shape. Moreover, these synonyms offer more variation and brightness to the description of things that resemble an eel and can make writing more interesting and engaging.