One of those kids you usually see in middle and high schools (the
age when
people start to assert their individuality) who are awesome at
art, take as many
art classes as they can, and are constantly drawing, painting, or photographing something. They often may be drawing on themselves or their belongings with sharpie marker.
Many also are highlly individualistic and may choose to die their
hair interesting colors, cut it it strange ways, or dress in a rather offbeat manner. Many also started various trends (such as wearing
Converse shoes) before they became mainstream.
Some are into theater or the performing arts. They are sort of a high school version of bohemians. (meant in the nonconformist sense of the word)
NOTE: (not at all to be confused with emo kids, as this is a totally different idea, though some
art kids are emo and some emo kids are artsy in nature.)