Planned for release within a couple of days, I have made these new NPC's available on our test server, available through this link.
The Lizardman Shamans can be found in the Lizardman Canyon, accessible through the Monsters teleport in your spellbook.
Just like OSRS, the Lizardman Shamans drop the Dragon warhammer. This weapon's special attack lowers your opponent's defence level by 30% while using up 50% special attack energy. It works against both players and NPC's and is therefore a very effective weapon in both PvP and PvM situations.
The Shamans have similar attacks to OSRS and their poison can hit up to 30 damage. You can counter the poison effect by wearing Shayzien armour, which can be obtained by talking to captain Babacus. The more Shamans you have killed, the higher tier Shayzien armour you can obtain and the more effectively you can counter the poison attacks. The highest level armour can be obtained after you have killed 500 Shamans.

Please let me know if you find any bugs or with to offer feedback about the Lizardman or the Dragon warhammer!