The King Blue Dragon is a dreaded two-headed dragon located in his lair, deep in the sewers underneath the city of Varrock. Despite being one of the weakest dragon boss encounters, players should not take him lightly, as he is still fairly powerful magic-class monster, and players should always take an Anti-dragon shield as his dragonfire breath is very deadly without protection. The King Blue Dragon can also be killed as a Slayer assignment for Blue dragons, and as a result he is a fairly popular boss among PvMers.