Bringer

Bringer is a creature type unique to Fifth Dawn. They are depicted as crystalline humanoid or beastly entities. Their nature transcends the metal ecology of Mirrodin.

There were five Bringers, all conceived as manifestations of the energy of the five "suns" (moons) of Mirrodin. Each of these rare creatures has a mana cost of MM, but can be played for instead of the mana cost. Each has base power and toughness 5/5, trample and a powerful ability that may be played at the beginning of the owner's upkeep.
 * Bringer of the White Dawn
 * Bringer of the Blue Dawn
 * Bringer of the Black Dawn
 * Bringer of the Red Dawn
 * Bringer of the Green Dawn

Bringer is a creature type that isn't supported anymore. It was used to unify a group of creatures, but the type has not been added to creatures thereafter.