It is a
skull and two
femur like
bones arranged in an
x underneath or below the
skull.
Pirates (they guys in boats, not the
WaR3Z D00Dz) commonly used it, typically on their
flags where it was referred to as the Jolly Roger.
As
pirates were seen as
evil villainous characters, their
symbols, including the
skull and
crossbones, have become synonymous with
evil and nefarious activities. With the advent of modern
teenage rebellion chic, they have maintained a presence in all sorts of forms in
pop culture.
I just got a keen
magnet of a
skull and
crossbones yesterday. I think its
cool, but I think
pirate stuff is
cool in general.