The Snake King is the highest rank possible for a Serpentine to attain within their species. It is usually a tailed Serpentine—one already the leader of his or her own tribe. The Snake King's powers include dominance over the other Serpentine, commanding ability, and high status overall.
After Pythor P. Chumsworth was released form his tomb, he proceeded to rally all of the Serpentine, and became their leader. He then unified them, and directed all their efforts to find the four Fang Blades. This was so that he could succeed in unleashing the Great Devourer. Eventually, he succeeded in unleashing the monster. However, it quickly ate him, along with Sensei Wu. Skales, his former second-in-command, then became the new Snake King. As of now, he retains his position, assuming he is still among the living.