(Real Name: General Duncan):Man-At-Arms is He-Man's closest ally, originally packaged in the Mattel toy line as the 'Heroic Master of Weapons'. He is Teela's adoptive father and the chief producer of the weaponry and vehicles used by the Heroic Warriors.
Since Man-At-Arms is actually a title, not a name, the character is also known as Duncan. The original minicomics depicted him as the last surviving member of a family of great warriors and inventors, who used the material resources at his disposal to aid He-Man. The cartoon portrayed Man-At-Arms as a mentor to Prince Adam, and as such he was one of the few people aware that Prince Adam and He-Man were one and the same.