Received from a barbarian spirit after lighting a pyre ship with chewed bones. Though this method has a much greater chance of obtaining a helmet compared to slaying metal dragons, Chewed bones themselves can only be obtained from Mithril dragons as a rare drop; or
Shortly after the release of PvP worlds, many players believed that dragon full helms were a drop from other players. Initially, a Jagex moderator denied this, however another Jagex moderator later confirmed that dragon full helms were indeed dropped on PvP worlds. On 16 June, 2009, the full helm was removed from the PvP drop table.
When the dragon full helm first came out, its stats beat the Third-age full helmet's original stats in each section. Jagex then updated the Third age full helmet, which made it slightly stronger than the dragon full helm.
Many players thought the helm would fall in price a while after its release, but the dragon full helm, being a very rare drop from mithril dragons, showed no significant signs of a price drop until the release of PvP worlds. Then, as a result of many dragon full helms coming into the game from PvP worlds, the price dropped significantly, from over 50m in September 2008 to under 10m by May 2009. Then, on the 16th June, 2009, dragon full helms were removed from the PvP world drop tables.
When receiving this as a drop from a Mithril dragon, it will appear on a player's adventurer's log.
When receiving this after constructing a pyre ship, a message appears on a player's adventurer's log, "While laying barbarian spirits to rest, I was given a dragon full helm."
In the early stages of the Evolution of Combat, Mithril dragons were commonly botted because of the way the ability system worked. When Jagex fixed this, all the bots then burned up the chewed bones resulting in many dragon full helms entering the game. This caused their price to drop from around 40m to 4m over the course of several weeks.