Autek Mor aka The Maimed, or Moonman was the Iron Lord and Iron Father to the infamous Clan Morragul of the Iron Hands legion during the Great Crusade and Horus Heresy, later becoming the first Chapter Master of the Red Talons. One of the original members of the Legion prior to its reunion with Ferrus Manus, he had already developed a reputation for being a weaponsmith and an asshole. He was reputed to rule his clan company with an iron fist and for having killed members of his own legion in duels over slights to his honour. When Ferrus was rediscovered and the Legion came to Medusa. Mor took over an outlaw clan's leviathan crawler in a single night of violence and made it his. As the years went by, Clan Morragul became a sinkhole for the outcasts and unstable elements of the Iron Hands, who fought and died under Mor's command. He also didn't really get on well with Ferrus, having no love for each other. As such he and his clan's had a shitty reputation and were generally regarded as outsiders in the Iron Tenth. Of course, Mor couldn't give a fuck.
When the biggest family drama began, Clan Morragul was part of the second wave of Iron Hand forces to arrive at Istvaan V. Unfortunately, his arrival was at the same time the Night Lords, Iron Warriors, Word Bearers and Alpha Legion pressed the "change team" button. Though they never really liked each other Mor valiantly tried to break through the traitor fleet to rescue Ferrus, unwilling to accept his demise. Alas, he was forced to retreat and escape with a handful of survivors.
While Shadrak Meduson rallied most of the survivors and fought guerrilla style, Autek Mor said "fuck that" and went about making war his own way. He gathered what forces would rally to his banner and launched a series of full-scale assaults upon worlds that the Traitors had captured or turned, allowing them to expend their strength and then destroying what remained with overwhelming force. It was a brutal strategy in which entire populations were to be allowed to fall while the Iron Hands stayed their wrath, yet it was one that made full accounting of the relentless calculus of war. With their force blunted by their invasion operations, the Traitors could be attacked at the moment of their supposed victory whilst at their weakest and obliterated without mercy.
Mor especially punished worlds that simply surrendered to the traitors without fighting. One such planet was liberated, only for the Iron Hands to immediately take off. Right as the inhabitants were beginning to celebrate their liberation, the timed atomic devices that Mor had set under all their major cities detonated, turning the planet into a radioactive ball of rock. What a dick. This however, would be nothing compared to what he did next...
Marshaling a force of Solar Auxilia, as well as elements of the Imperial Fists, Autek Mor attacked the planet of Bodt, the fief world of the World Eaters where Angron had first taken command of his legion. Now, Mor could've done his usual thing and attack with maximum rip and tear, but then he realized that wasn't metal enough, and so decided to crash the FUCKING MOON INTO THE PLANET instead. The entire population of Bodt--traitor marines, Sarum Mechanicum and Legio Titanicus--was destroyed, which not only was a blow to the World Eaters' recruitment but to the overall traitor cause. Mor himself would not participate on the main assault. He would spend the battle conducting his own mission of retrieving a stasis casket from a hidden vault, while the rest of the planet was mooned into oblivion.
After the Horus Heresy, Clan Morragul became the Red Talons Chapter and Mor became its first Chapter Master.
TLDR: Autek Mor was an angry toaster marine in a legion of toaster marines and he got shit done
Former Thunder Warrior
Mor's borderline (being generous with that) insane aggression has lead even in-universe speculation that he isn't your run of the mill Iron Hand, that something was different in his creation. His habits and mannerisms also mirror that of behaviors seen in known Thunder Warriors like Ghota and Arik Taranis. Combining this with that he was one of the very first Xth legionnaires created, and with other HEAVILY "hinted" Thunder Warriors among the Astartes, like Endryd Haar, has lead many to suspect that Autek Mor may have also once been a Thunder Warrior.
On the Tabletop
He's an Iron Father with Cataphractii Terminator armor, +1S, +1T (but -1In and -1 attack), a Servo-Arm, a Paragon Blade and a Volkite Charger for gear. With Fearless, the Iron Father upgrade and Preferred Enemy (Infantry) Mor is a complete and utter goddamn beast with 3 base attacks (S6 w/ 6's to-wound causing ID) +1 Servo arm attack (S8 w/ Unwieldy). All of that at AP2. Oh, and with Inviolate Armour and T5 he can't be ID'ed by double Toughness from shooting.