The Metal Masked Assassin is a villain in the cartoon series Metalocalypse.
He is the brother of Agent 216, whom Crozier had sent to kill Dethklok in "Murdering Outside The Box." He is voiced by George "Corpsegrinder" Fisher of the real-life band Cannibal Corpse. He is a mysterious psychopath who wears a metal mask and regularly dismembers people hanging from hooks (a reference to the Cannibal Corpse song "Meat Hook Sodomy",), apparently while they are still alive. General Crozier recruits him for the assault on the Dethwater concert, supposedly so he can avenge his brother's death, although Crozier has ulterior motives. As he prepares to kill Skwisgaar and Toki, he is seriously wounded by Ofdensen, who breaks his right arm, stabs him in the kidney, and kicks him into a body of water.

He returns in the episode "Dethvengeance," alive but now wearing a metal support for his formerly broken arm. He forms the Revengencers with Edgar Jomfru, who escaped from Dethklok's underground prison. He seems to have developed a grudge against Ofdensen and wants him dead, realizing that doing so would cause Dethklok to fall apart and make them easier to eliminate. It should be noted that in subtitles he is referred to as "Selatcia" though the connection remains unclear (it is most likely an error). In "The Revengencers", he expresses his pure hatred for Ofdensen, devoting himself to "crucify[ing]" the man who protects Dethklok. During Dethklok's concert at the hospital, he kills a guard, steals his hood, and sneaks up on Ofdensen, catching him by surprise. He quickly overpowers the surprised manager and throws him out of a window which is many stories high; but Ofdensen somehow lands on his feet, virtually unharmed. He then gathers up the other members, as the Revengencers' presence has been discovered, and escapes. In "Black Fire Upon Us", he is shown to have eluded Ofdensen's numerous attempts to find him, and fronts the assault on Mordhaus itself during their CD release party. He personally fires the main weapon that brings Mordhaus' shields down and sets the building on fire. Ofdensen leads the counter-attack, personally destroying the main weapon, but the Metal Masked Assassin steals one of the Dethsoldiers' hoverbikes and chases Ofdensen down a long passageway in Mordhaus. After the teenager Revengencer shoots Ofdensen with a crossbow, piercing him completely through the chest and knocking him off the bike; The Metal Masked Assassin then begins beating Ofdensen mercilessly, and pulls out a knife to torture him with before he dies; Ofdensen gasps slightly in response, but does not move otherwise. As he is about to stab Ofdensen, Nathan Explosion knocks Metal Masked Assassin out with a large, flaming wooden beam, and says "That's my bread and butter you're fucking with."(A direct reference to 'The Metalocalypse has Begun', in which Ofdensen said the same thing when the Assassin was trying to kill Skwisgaar and Toki.) It is unclear what happens to him after this; however the final scenes show Ofdensen lying motionless and wounded, while the members of Dethklok stand motionless over him. While it was revealed at the beginning of Season 3 that he failed in killing Ofdensen, his fate after being struck by Nathan remains unclear. The relationship between Ofdensen and the Assassin is that of mutual enmity and grudging respect. In their initial meeting the Assassin had his guns pointed at Ofdensen who simply took off his tie with his hands at his sides, a direct challenge to the Assassin. After being beaten with his arm broken and stabbed with his own knife the Assassin focuses most of his rage on Ofdensen. While this is due to the fact that he was beaten it is also because he only views Ofdensen as a genuine threat stating that Dethklok is nothing without Ofdensen. After almost being killed in their second encounter Ofdensen likewise sees the metal masked Assassin as a true threat by telling the elite Klokateers to watch out for him specifically and another Klokateer walking in afterward saying that they still haven't found him. Ofdensen expresses his frustration in this by stating "Where are you, you son of a bitch".