Obtained from the Pk Point shop for 5000 Pk Points or by trading other players.The Serpentine Helmet is the most powerful helmet in game. The Uncharged Serpentine Helmet needs to be charged with 11,000 Zulrah Scales. (note: You do NOT need to fully charge it to use it.).
The Serpentine helmet has a venom effect when attacking players. This venom starts low and works it's way up to hitting 20. To stop the venom, you need to drink an Anti-Venom potion.