History and specifics
These warriors are trusted absolutely and may even become a member of the Great House they serve for their continued role. This is simply because the Gin'tak puts the good of the House he serves above all other considerations, including ones regarding personal honour which is a driving force with Klingon society. Should the Gin'tal believe that a member of the House is endangering the family then they are entitled to invoke the right of Ya'nora kor. (TNG episode: "Firstborn")
K'mtar was ghIntaq to the House of Mogh in 2370. That year, a future version of Alexander Rozhenko assumed the identity of K'mtar to gain the trust of Worf and prevent his untimely death. (TNG episode: "Firstborn")
- There is a Klingon weapon known as the ghIntaq which may have inspired the naming of this role within Klingon society or the position may have been the inspiration for the weapon's name.
The title of Spear was one given to Klingon warriors of the Klingon Empire in an alternate timeline where Humanity never existed and an endless war continued between the Klingon Empire and the Romulan Star Empire.
The purpose of a Spear was to take command of heavily armored ships which were piloted by two Spears and ram them into the Romulan warships. The enemy ship and its crew would be lost at the cost of two Spears which was deemed an acceptable loss by the Empire in order to destroy their hated enemy. It was a tactic of desperation but was turning the tide of the war allowing the Klingons to gain the advantage.
Being granted the title of Spear was considered a great honor among those who are given the position as those warriors who serve the role of a Spear are never expected to return. The unique suicidal ships they pilot possess escape pods for the two Spears in order for them to be used on further ramming operations. In order to prevent capture, these warriors also carry detonator belts which would kill them in order to prevent capture by Romulans. (TOS novel: First Frontier)