Slender Man is the fictional character seen in the video game "Slender". Slender Man (aka Slenderman) originated as an unidentified internet character, created by user Victor Surge's Something Awful forum in 2009. He is depicted as a slim figure, resembling an unnaturally tall man with a blank face and usually shapeless wearing a black dress. It is commonly said that Slender Man stalks, kidnaps or scares people, especially children.
Steps
Method 1 of 2: Draw Slender Man

Step 1. Draw a sketch of a man with very long arms

Step 2. Sketch the basic outline to build the figure

Step 3. Draw the clothes and other details
Leave your face blank.

Step 4. Optimize the drawing using a fine point tool

Step 5. Draw the contours above the sketch

Step 6. Erase and remove sketch marks

Step 7. Add the colors
Method 2 of 2: Draw Slender Man with Tentacles

Step 1. Draw a rough outline of Slender Man's structure and posture

Step 2. Draw the shapes to build the figure

Step 3. Draw the outline for the tentacles

Step 4. Define the shape of the tentacles

Step 5. Draw more details and clothing

Step 6. Optimize your masterpiece using a fine point tool

Step 7. Draw the contours above the sketch

Step 8. Add the colors

Step 9. Optional:
draw scary dark background and terrified child if you want to create scary scene.