WEAPONS MASTER OF ETERNIA
Man-At-Arms
Duncan is Eternia's weapons master and inventor, the man who raised Teela and one of the few who know Prince Adam is He-Man. Mattel's later cardbacks add a twist: Man-At-Arms is an office, and Duncan is neither the first nor the last to hold it.
Man-At-Arms is Duncan, weapons master of Eternia, adoptive father of Teela, and one of the few who know Prince Adam is He-Man. Man-At-Arms is also a job title, handed down to him, and one he eventually loses.
FILMATION, 1983
Weapons master, inventor, and the man who raised Teela
In Filmation's He-Man and the Masters of the Universe, Man-At-Arms is the palace weapons master and its resident inventor, a mustached engineer in helmet and armor who is as likely to be found in his workshop as on a battlefield. He is in the very first episode, "Diamond Ray of Disappearance," shown on September 5, 1983, where Skeletor's new diamond banishes him along with King Randor and Queen Marlena, and he is one of the handful of people who know that Prince Adam is He-Man.
The next day's episode, Paul Dini's "Teela's Quest," gives him a past. The Oracle of the Crystal Sea tells Teela that the Sorceress of Grayskull is her mother and that Man-At-Arms adopted her as an infant, and the Sorceress wipes the memory once the danger is over. From then on he carries two secrets, Teela's and Adam's, and the series never asks him to account for either.
Filmation was slow with his personal name. Duncan is spoken on screen in "The Problem With Power," first shown on November 9, 1984, early in the second season.















Man-At-Arms in the Wind Raider, flying out on the mission.
Clipped from our own copy of He-Man and the Masters of the Universe, Island of Fear (), 4:23 to 6:21, 1 minute 58 seconds. Nothing is added and nothing is sped up. Copyright Mattel.
HIS BEST EPISODE
The engineer who tried to quit
David Wise's "Day of the Machines," first shown on September 19, 1984, is the episode most interested in the man behind the gadgets. A remote-control rocket from one of his experiments slips its leash, crashes into a royal chamber and nearly kills the King and Queen, and almost at once Man-At-Arms has decided that the only honorable thing to do is resign. Nobody else in the room agrees with him, and the script is careful to make the accident nobody's fault.
Skeletor does not cause the crash; he only notices it, and slips an energy bug called Byte into the royal computers while a good engineer is busy doubting himself. Once Byte is loose the palace machines turn on everyone, Man-At-Arms included, and a man who has just tried to give up his job has to keep doing it. Teela's closing moral tells viewers to own a mistake and not shift the blame onto others.
THE SAME VOICE ON BOTH SIDES
The mentor and the villain, one performer
Alan Oppenheimer voiced Man-At-Arms in the Filmation series. He also voiced Skeletor. Both characters are in most episodes, so the hero's mentor and the villain trying to kill him are the same performer arguing with himself.
THE FIGURE TO OWN
Man-At-Arms on the shelf now
Mattel's Origins line, built on the proportions of the vintage toys, sells him in his 2002-series look as part of the 200X Cartoon Collection. The Chronicles figure from the 2026 film is the other one in stock.
Masters of the Universe Origins 200X Cartoon Collection Man-At-Arms Action Figure
Buy at BigBadToyStore, $19.79 Paid link
Full details and photosPrices and stock read from BigBadToyStore on November 2, 2026. In collaboration with BigBadToyStore. #BBTSpartner
A POST, NOT A NAME
Two centuries of weapons masters, and Duncan is the middle one
Mattel's Masters of the Universe Classics cardback opens with a sentence most retellings skip: "REAL NAME: Duncan. For two centuries, the Eternian weapons master and combat instructor to the royal family has been called the 'Man-At-Arms.'" Man-At-Arms is an office. Duncan holds it. Others held it before him and, as it turns out, someone holds it after him.
The rest of the card sets out his career. Duncan was trained by the renowned tactician Dekker and came through the Great Unrest as a veteran of it. King Randor then asked him to take the post and to fortify the royal guard with an elite strike force, which Duncan named the Masters of the Universe, so the team's name is his coinage. The card also makes him a great inventor, crediting him with an electronic version of the Sword of Power for Adam to use until Adam could unite both halves of King Grayskull's sword, and it closes on Duncan and his adopted daughter Teela scouting the borders of Eternia for signs of lurking evil.
Mattel's Dekker card tells the succession slightly differently. Dekker was a mercenary from the Dunes of Doom who switched sides during the Great Unrest, became King Miro's Man-At-Arms, took "a young prodigy named Duncan under his wing," and then retired to Orkas Island "passing his title and duties to his former apprentice and sidekick." So Dekker's card says Dekker handed the post on, and Duncan's card says Randor asked him to take it. Both are official, and they are not quite the same event.
THE CARD WHERE HE STOPS BEING DUNCAN
The grimmest bio in the whole cardback set
The Classics line released a Snake Man-At-Arms figure, and its bio is the grimmest thing in the whole cardback set: "REAL NAME: Duncan of the Viper Clan. Exposed to the Serpent's Ring, Duncan was magically transformed by King Hsss into a Snake Man permanently."
The rest of the card follows that through to the end. Under the spell he uses his genius to build great and horrific machines of war for the Snake Men. He is replaced as Royal Man-At-Arms by Clamp Champ, is forced to fight him, and is mortally wounded in their final duel at the Second Ultimate Battleground, recovering his own humanity for a moment beforehand thanks to a spell cast by his daughter Teela, by then the new Sorceress of Grayskull. Nothing about it is a curse waiting to be broken in the third act, and the inventiveness that made him useful to the heroes ends up arming their enemies.
Clamp Champ's card confirms the succession from the other end. Raenius, formerly King Randor's bodyguard, stepped in as the new royal Man-At-Arms after Duncan was captured and turned. The card is candid that Raenius is not the equal of the man he replaced: he lacks Duncan's skills as an inventor, and proves himself instead through hand-to-hand combat and weapons knowledge, particularly the techno clamp that gave him his nickname. He leads the Masters of the Universe all the way to the Second Ultimate Battleground.
TEELA
Two secrets, kept from the person he raised
Duncan's card calls Teela "his adopted daughter," and Teela's own card calls her "the adoptive daughter of Duncan, the current Man-At-Arms." The Sorceress card explains how it happened: Teela'Na, the Sorceress, was cloned by Skeletor, saved the resulting child with Man-At-Arms's help, and gave the baby up to him to raise.
Filmation's version keeps the same arrangement and never makes him answer for it. Revelation does, and that is most of what Liam Cunningham's performance is doing: an older Duncan whose moral authority holds the cast together during He-Man's absence, framed as a grieving father.
IN BRIEF
Man-At-Arms, year by year
Filmation introduces him
He is in the premiere, "Diamond Ray of Disappearance," on September 5, 1983, and the next day's "Teela's Quest" reveals that he adopted Teela as an infant.
"Day of the Machines" puts him at the center
An experiment goes wrong, he tries to resign, and Skeletor uses the moment to set an energy bug loose in the palace computers.
The Snake Man-At-Arms card ends his story
Duncan is permanently transformed by King Hsss, builds war machines for the Snake Men under the spell, is replaced by Clamp Champ, and dies fighting him at the Second Ultimate Battleground, restored to himself for a moment by Teela's spell.
Clamp Champ's card names his successor
Raenius, once King Randor's bodyguard, becomes Royal Man-At-Arms after Duncan is lost, completing the line of office holders Mattel's Classics cards lay out from Dekker to Duncan to Clamp Champ.
Revelation makes the secrecy the point
Liam Cunningham voices an older Duncan whose moral authority holds the cast together during He-Man's absence, written as a grieving father who has kept two secrets from the daughter he raised.
Idris Elba in the live-action film
Elba plays Duncan in the film released in June 2026, with James Purefoy as King Randor and Kristen Wiig voicing Roboto.
Questions
Man-At-Arms questions, answered
What is Man-At-Arms's real name?
Duncan. Mattel's Classics cardback gives it plainly, and Filmation first says it on screen in "The Problem With Power," first shown on November 9, 1984.
Is Man-At-Arms Teela's father?
He is her adoptive father. Mattel's cardback for Teela calls her "the adoptive daughter of Duncan"; her biological mother is the Sorceress of Castle Grayskull, who gave the infant to Duncan to raise. Duncan knows this and does not tell her.
Does Man-At-Arms know Adam is He-Man?
Yes. In the Filmation series he is one of four who know, alongside Orko, the Sorceress and Cringer.
What happens to Man-At-Arms?
In Mattel's Classics timeline he is exposed to the Serpent's Ring and permanently transformed into a Snake Man by King Hsss, builds war machines for the Snake Men under the spell, is replaced as Man-At-Arms by Clamp Champ, and is mortally wounded fighting Clamp Champ at the Second Ultimate Battleground. This does not happen in the Filmation series or in the 2026 film.
Who is Clamp Champ?
Raenius, formerly King Randor's bodyguard, who became Royal Man-At-Arms after Duncan's transformation. Mattel's card for him states outright that he lacked Duncan's skills as an inventor.
Who plays Man-At-Arms in the 2026 movie?
Idris Elba. James Purefoy plays King Randor, though several early listings had the two the other way round.
Was Dekker the first Man-At-Arms?
Mattel's cards suggest he is the one before Duncan, not necessarily the first ever. Dekker's own cardback says he was a mercenary from the Dunes of Doom who switched sides during the Great Unrest, became King Miro's Man-At-Arms, trained "a young prodigy named Duncan," and eventually retired to Orkas Island, passing the title to his former apprentice. Duncan's card tells it slightly differently, with King Randor asking him to take the post. Both are official and not quite the same event.
Does Duncan get his humanity back after becoming a Snake Man?
Briefly, at the very end. Mattel's Snake Man-At-Arms card has him mortally wounded in single combat with his own successor, Clamp Champ, and restored to himself for a moment beforehand by a spell from his adoptive daughter Teela, by then the new Sorceress of Grayskull, before he dies.
Who is Malcolm, and how is he related to Man-At-Arms in the 2026 film?
His younger brother, per the film. Mattel's own cardback for the character also named Malcolm (Fisto) makes him the older of the two; the 2026 film keeps the relationship and reverses the order.
Compiled by the heman.org desk from the Filmation episodes Diamond Ray of Disappearance, Teela's Quest, Day of the Machines and The Problem With Power and their credited cast lists, Mattel's packaging and Classics cardback copy, published cast lists for the 2026 film, and current Big Bad Toy Store listings.
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The Archive
Every Man-At-Arms figure
Save 55% Core Man-At-Arms Mattel Buy, $5.40 Paid link
Eternia Minis Man-At-Arms Mattel · 2021 Archive only
Super7 Vintage - Man-At-Arms (Crystal) Super7 · 3 Archive only
Super7 Club Grayskull - Man-At-Arms Super7 · 1 Archive only
Snake Man-At-Arms Mattel · 2012 Subscription Archive only
Snake Man-At-Arms (200X) Mattel · 2004 Archive only Alongside