Transmortals are a group of beings appearing in N.D. Wilson's Ashtown Burials series. A transmortal is simply an ordinary mortal who somehow becomes immortal. Thus they have transformed from mortal, to immortal. There is no common way to become a transmortal. Some have eaten of the Fruit of Life, or drank of the Fountain of Youth. Others become immortal by possessing a powerful object, such as the Odyssian Cloak, or Dragon's Tooth. It is also a result of some blessing or curse.
Wilson commonly chooses semi-famous people from history and mythology to give this transmortality to. In the first book of the Ashtown Burials, The Dragon's Tooth, Maximilian Robespierre, the leader of the French Revolution, is revealed to be a transmortal. In later books, legendary people like Gilgamesh of Uruk, Arachne, and Captain John Smith are introduced, all being known in the real world, and given transmortality by Wilson.
A common trait among transmortals is grief, which often leads to violence. In truth, the transmortals are tired of living forever. The Order of Brendan will bury the most dangerous of the transmortals, while making power-limiting treaties with others. Many transmortals desire the burials, where they can endure life in sleep. There are few ways to kill transmortals, the Dragon's Tooth being the most famous. Many weapons were made with the charm of the tooth, and can cause pain when used on transmortals, but do not kill unless the Tooth itself is present. Several times, when Cyrus Smith has the Dragon's Tooth, his allied transmortals will plead for him to end their misery.