Shadow Demon

Shadow Demon (シャドウ・デーモン) is a level 30 demon that is used by Nazarick's field agents as an emergency shield.

Appearance
Shadow Demons are like shadows without thickness expanded from the darkness. From an observer's point of view, it was as if something two dimensional had gained a third dimension. They resemble emaciated humanoid figures with bat wings attached to their backs, their fingers ending in sharp claws. Their figures are pitch black, as if created from darkness itself. The only other color were the eyes, a sickly glowing shade of yellow.

Abilities
Shadow Demons possess a special ability called 'Shadow Warp,' allowing them to transverse at short distance between shadows. As implied by its name, Shadow Demon could morph into shadows, it is a monster that excelled in stealth. As shown with Sebas's case, a Shadow Demon is also capable of hiding within a person's shadow and leaving it.

Trivia

 * Shadow Demons are used as protection for the NPCs and Ainz every time they are outside the Great Tomb of Nazarick.
 * In the Web Novel, Narberal Gamma uses Shadow Demons to collect information around E-Rantel. When wounded, they spew a thick black fluid as blood.