Thug
The
Thug was intended to be a frightening character upon first appearance, yet
would be acceptable in the end when his true intentions shone through. His
round shape is associated with a circle-- a friendly shape.
As explained under Symbolism, he has slits for his eyes because he is able
to "see" from the beginning.
His mask is reminiscent of an executioner's because he does kill the Painter's
hopes by destroying his work.