Castellan

Looks like a Cockatrice, but his look will change soon.

Statistics

This monster has Mirror Skin Perk, I Glow in the Dark and possibly other perks. Has some immunity for Magic, Radiation, Heat and Cold damage. Because it uses its 500 Potion of Great Healing and Staff of Protection its health can reach 72000HP while fighting, hardly goes below 20000HP at first time. Besides 500 GHP it carries Poison Antidote potions which it uses to stop poison and 2000 Point Defense. It ignores Monster Magnetism Perk or Monster Magnetism Cloak, has no True Sight. Every new spawned monster have different build with a random weakness.

drops are not final
~70-200k gold coins
some Poison Antidote
Staff of Protection (possibly break while fighting)
Golden Star Mace (possibly break while fighting and the opponent can be BroDded as well)
Nexus Removal Stones (20% chance to get a Nexus Removal stone)
Point Defense (if wasn't used while in combat)