This is hanging from a tree near Interstate 30's Exit 123 at Bryant. The Bryant Public Safety Department received a call about it and reported that it is a Halloween decoration. It may be related to nearby advertising for a Halloween event. Others see more threatening symbolism than trick-or-treat. The picture and assorted commentary have been making the rounds in the black community. "It has no place in 2009," said one e-mail in a string I received.
UPDATE: Here's info on the commercial Halloween attraction that uses this as a prop.