Mithril dragon

Mithril dragons are found in the Ancient Cavern, which may be accessed by starting the Pyre ship section of Firemaking in Barbarian Training. The dragons have extremely high defence, but since they are made of metal, they are weak to magic. Mithril dragons are often killed for their possible drop of a Dragon Full Helm.

Mithril dragons are currently the strongest dragons. Their release shattered the King Black Dragon's long standing record as being the strongest dragon in RuneScape.

Habitat
The Ancient Cavern.

100% drop

 * Dragon bones
 * 3 Mithril bars

Weapons

 * Rune battleaxe (common, may also drop 1-5 sharks in the same kill)
 * Rune spear (uncommon)
 * Rune mace (common)
 * Rune 2h sword (rare)
 * Dragon spear (extremely rare)

Armour

 * Dragon full helmet (very rare)
 * Rune full helmet (common)
 * Dragon medium helmet (very rare)
 * Rune Sq Shield (rare)

Arrows and runes

 * Rune dart (p) (14)
 * Adamant dart (p) (20) (rare)
 * Rune knife (8-18)
 * Rune javelin (8-30) (common)
 * Blood rune (27) (common)
 * Soul rune (10)
 * Nature rune (67) (rare)
 * Rune arrow (8) (uncommon)
 * Rune bolts (10-27)
 * Law rune (45) (very rare)

Potions

 * Super attack potion
 * Super strength potion
 * Super defence potion
 * Super attack mix
 * Super strength mix
 * Super defence mix
 * Prayer mix
 * Prayer potion

Other

 * Coins (600-3000) ( 600 is common, anything above is rare)
 * Shark (1-6) (common, also dropped alongside other drops, such as Rune battleaxe)
 * Runite bar (1, 2, 3) (common)
 * Gems
 * Nature talisman (rare)
 * Silver ore (100 noted) (very rare)
 * Herbs
 * Uncut gem
 * Ancient page
 * Chewed bones
 * Clue Scroll (Level 3)
 * Tooth half of a key (rare)
 * Loop half of a key (rare)
 * Dragon shield half (very rare)
 * Draconic visage (extremely rare)
 * Mithril Dragon Tail-Bone (Uncommon, after Fur 'n' Seek quest for second wishlist)
 * Dragonstone (extremely rare)

Trivia

 * Mithril Dragons are the only Slayer task that Duradel, Lapalok and Kuradal do not give advice for; "You are a battlemaster; test your skills."
 * Mithril Dragons are currently the only Metal dragons that do not drop Dragon Platelegs or Dragon Plateskirts.
 * In order to receive a Dragonkin key, you must take the Strange key loop and Strange key teeth (both obtained from While Guthix Sleeps) to the Mithril Dragons, and use one of the halves on a dragon. It will animate as if it's breathing fire at you, but does not do any damage. Afterwards it's temporarily tolerant to you, giving you time to run away. During the fusing of the key, the Mithril dragon will temporarily appear as level 57.
 * In the postbag from the hedge, Oziach pointed out that there are bronze dragons, iron dragons, steel dragons, and mithril dragons when he was chatting with Evil Dave. Oziach deduced that there will be adamant and rune dragons. But that's not the end, Evil Dave saw where Oziach was going. 'Eventually, somewhere in Runescape there must be dragon dragon,' Oziach said. Fortunately, there are no Barrows dragons or Third-age dragons (although there are theories of the fabled White dragon).
 * It may be possible to receive a Dragon Full Helm and the Dragonic Visage in the same drop since the visage is not considered part of the main drop.