Black Iron Tarkus

Black Iron Tarkus is a character in Dark Souls. He can be summoned by the player in the fight against the Iron Golem boss in Sen's Fortress.

Location
In a tower structure at the end of the walkway to the right from where the fog door to the Iron Golem is located. Like other summon signs, Tarkus' summon sign is only visible if the player has not put down a summon sign and is in Human form.

Plot
Tarkus aids the player in taking on the Iron Golem as a White Phantom. He is incredibly tough, and can serve as a distraction during the Iron Golem battle. In fact, Tarkus can solo the boss in the first play-through, and stands a break-even chance of doing so on future play-throughs with minimal support from the player.

His Greatsword, Black Iron Greatshield and armor (Black Iron Set), are found on his corpse in Anor Londo, next to the entrance to the Painted World of Ariamis. A Painting Guardian stands next to his corpse, possibly removing it from the room since the body is so far away from the entrance.

Lore
Black Iron Tarkus is most likely a knight of Berenike, and is renowned even among his fellow knights for his great strength. This makes him one of the longest surviving knights to attempt at curing Undeath and fulfilling the prophecy. He defeated the Iron Golem and as the only sole prevailer, carved his summon sign so others who eventually came as far as him would be assisted by his phantom.

According to the Crestfallen Merchant, Black Iron Tarkus met his doom while attempting to visit Anor Londo. This proves true, as his body can be found in the hall of the Painting Guardians.

Trivia

 * Many players favor Black Iron Tarkus due to his immense strength, his reliability in PvP and his ability to solo the Iron Golem with minimal support.
 * Black Iron Tarkus seems to be loosely based on another character, who is also named Tarkus, from the 1987 manga Jojo's Bizarre Adventure (more exactly from Part I: Phantom Blood). Not only do they share the same name, but they also share other similar traits, such as an inhuman strength and the fact that both characters wield greatswords in battle.
 * Tarkus is also the Estonian word for "wisdom".
 * Even though it says that Tarkus's armour was unwieldy to all but Tarkus himself, when summoned for the fight against the Iron Golem he "fat rolls" due to not having enough endurance.