Shadow asp

Shadow asps were shadowy creatures often found in tombs. They were among the species counted as serpents by the Scaled Ones.

Description
Shadow asps were serpents with dark, patternless scales, which made them difficult to see in shadows. They often appeared slightly translucent.

Behavior
Although smarter than most nonmagical snakes, shadow asps were still beasts that acted on instinct.

Abilities
Shadow asps, as magical beasts, possessed a few nasty magical surprises. They could become incorporeal at will for up to an hour every day. They were also venomous, and any creature slain by their venom would rise as a shadow within 2 days, uncontrolled but bound to the location they died in as a guardian, unable to move more than away from where they rose.

Combat
Shadow asps preferred to attack by becoming incorporeal, then emerging from the walls, floor, or ceiling en masse to bite potential prey, then retreating to let their venom take effect. They were often accompanied by the shadows their venom created.

Ecology
Shadow asps were thought to have originated on the Plane of Shadow, but were often found on the Material Plane in dungeons and tombs, as their venom made them useful guardians of such sites. They were also found near portals to the Plane of Shadow and in remote locations in the Underdark. They were naturally both watchful and quiet, and lived either alone or in clutches of 3 to 12 shadow asps.