The Darklurker is a being shrouded in mystery. What it actually is, is unknown, whether it be a golem, a part dragon or the remnants of something else. The Darklurker lives in the Dark Chasm of Old. It awaits one who would light the torches in the 3 fragments of the Abyss across Drangleic, and thereby agitate the Dark to action and most probably expansion.
After lighting a torch in each of the Dark Chasm of Old locations and defeating the phantoms there, the Player will drop down to exit the world, but instead of exiting they will be ambushed by the Darklurker. To lurk is to remain hidden or await ambush for someone, so the Darklurker lives up to its name.
The Darklurker is capable of wielding various forms of magic, teleportation and cloning of itself. It can hurl projectiles of pure dark, creating Dark Greatswords, become invisible and summon forth orbs of fire that will track the Player. Its ability to create a clone of itself is similar to that of the Four Kings of New Londo.
The Darklurker’s soul is not dark like Velstadt, Raime, the Throne Defender and Throne Watcher or any of the Sisters of Dark. It is a light coloured soul. The Darklurker itself also has a high resistance to Dark damage. These two facts indicate that the Darklurker is not a native to the Abyss, and has instead invaded it. If this is the case, then it makes sense that the Player should be rewarded for destroying the Darklurker by Darkdiver Grandahl, as his purpose seems to be to spread the Dark in Drangleic. If the Darklurker is not native to the Abyss then this means it is able to survive there and perhaps even halt its progress.
The Dragon Chime, a reward for defeating the Darklurker, has an interesting connection to it. Both the Darklurker and Dragon Chime have spent much time in the Dark Chasm of Old, and yet they do not appear to have become infused with Dark. The Darklurker has a light soul, and the Dragon Chime has sublime purity despite sitting long in the Dark Chasm. Perhaps its connection to the dragons has kept it from succumbing to the Dark, and if this is the case, then perhaps the Darklurker is somehow related to the dragons? Its body consists of mostly feathers, and the Aged Feather allows us to teleport like the Darklurker can, even showing the same animation as when the Darklurker teleports – numerous feathers filling the air around the user.
The Darklurker also shares some resemblance with the Leydia Pyromancers. Their hood and coloring are similar and their range of spells are as well, save that the Darklurker uses Dark instead of magic. The Leydia Apostles are all connected with the Dark, and seem to have a strong presence in the Undead Crypt. There is a seemingly endless row of massive statues depicting them along the edge of the abyss that fills the Undead Crypt.
Whatever the case, the Darklurker remains a mystery whose answer is yet to be discovered.