I have a copy of Serpent Kingdoms, and I could use this to eke out an article on the Ssarak. Some possibilities:

* The Yaun-Ti could be used to represent Ssarak. But they could also represent the Children of the Serpent.

* The Ophidians in Serpent Kingdoms could work for Ssarak. They are not as well known as the Yuan-ti and have the same basic background. Humans who have corrupted or been corrupted into a mix of human and snake.

* Finally, the Sarrukh. Not something that Azrai would create, I admit. But maybe he did. After all, he is a god. The Sarrukh is one of the progenitor races of Faerun, and probably could make for an interesting beast-man race.