Per 
This is an idea of an SCP, and also my first SCP! Don't go easy on me, constructive criticism is essential for my improvement, so tear me apart.
The idea:
Description:
The shadow walker is a being that has the appearance of a male and is 183 cm in height. It appears to be covered in an unknown black substance that has been observed to leak from its body in all areas, however, the substance is not lethal to humans and animals, however, it does cause plants and flowers to be touched by the substance to decompose at an exponential rate.
The shadow walker is a being that seems to enter the shadows of any living organism. It can not enter the shadow cast from a building or object but can enter the shadow of a living organism. It has been observed to travel between the shadow of two organisms if the shadows are connected. Once not being observed by anyone, the being would pull the organism into the shadow, causing the shadow to disappear, However, once another organism enters the location and a light is cast onto the individual, the being reappears. It has also been observed to walk to the closest shadow being cast by a living being.
It was discovered in [REDACTED] off of the coast of the sea of Okhotsk in Russia. It was found after a young boy turned the lights of his room on causing the being to extrude from the boy's shadow. SCP Foundation agents were sent to the area and contained the being using floodlights to stop the being from entering the shadow of any foundation agents. All documents made by local police of the situation was purged.
Containment
SCP *insert number here* is to be placed in a cell 1.8 x 2.4 meters in length and width and 2.4 meters in height. The cell is to be always watched by at least two guards as the destructive power of the being is unknown although it is assumed to be very weak. Floodlights must always be on to make sure that it does not hide in the shadow of any personal and agents.
Tests must always be scheduled a week in advance to allow personal time to adapt the cell for the test. If a D-class subject is to placed into the cell, the floodlights must have enough power to operate the entirety of the test.
Currently, SCP *insert number here* resides in site-20 and any attempts to move it must be authorized. To move SCP between cells, a light carried by foundation agents must always be placed on it at all times. A D-class subject must stand at most 5 meters in front of SCP. Personal are equipped with suits that emit a light bright enough to rid the person of any shadow except the subject. The SCP will walk towards the closest shadow, once it does this, the subject must walk towards the area of containment.
