Logan's Run DMC Hammer to Fall of the Roman Empire Strikes Back in Black Eyed Peas

(Logan's Run)
(Run DMC)
(MC Hammer)
(Hammer to Fall, by Queen)
(Fall of the Roman Empire)
(The Empire Strikes Back)
(Back in Black)
(Black Eyed Peas)

The octagon?

Bears, beets, Battlestar Galactica.