Be careful in the lair, as the other two kings can hurt you if you are not using their specific protection prayer.
The Dagannoth Supreme launches spines from his back that hit several people at a time. It's best to melee the Supreme because when he launches his spines, people who are further away are more likely to be hit than those standing near him. Melee is Supreme's weakness. Also if you can get behind him that is great, as he only launches spines in front of him. As long as you have protect from ranged on, he isn't really that difficult. Make sure that if you're fighting Supreme, somebody has the other kings taken care of so that you don't get hit by more than one at a time.
The dagannoth king responsible for the death of the Bukalla.
Clue scroll (level-3), Clue scroll (level-4), Rune kiteshield, Rune 2h sword, Rune battleaxe, Dragon med helm, Shield left half, Dragon hatchet, Seercull bow, Archers' ring, Archer helm
Dagannoth bones (100%), Dagannoth hide (100%), Coins (972-3000), Steel kiteshield, Oyster pearl, Opal bolt tips (18), noted Yew logs (75-122), noted Maple logs (15-25), Shark (5), Iron knife (259-492), Mithril knife (27-48), Rune thrownaxe (7-9), Rune javelin (5), Uncut gems, Fremennik sword, Fremennik shield, Spined body, Spined platelegs, Red d'hide vambraces, Iron arrow (417-502), Law rune (514), Steel arrow (123-240), Adamant dart (11-18), Black platebody, Fremennik helm