In the Xanth sequence by Piers Anthony, the Naga certainly are a race of human-headed serpents that can transform involving totally human and serpent varieties, such as any species and size of snake. Nagas surface within the Dungeons & Dragons roleplaying activity, depicted as large serpents with human heads. https://andersonwkxju.blogminds.com/23naga-for-dummies-25575169