black flag Jolly Roger Pirate Flag pirates Skull and Crossbones beware black bones crossbones dangerous dead death death's flag halloween hazardous head pirate skull white aged antique backdrop background bone creepy cross crossbone danger evil free gray grey grime grimy grunge grunged grungy image jolly old omen ominous page paper photo photograph picture piracy resource retro roger scary sheet skeleton somadjinn stock texture textured vintage warn warning adventure ancient buccaneer captain death at sea fear fighting hat horror killing knife murder pirate ship pirates of the caribbean plunder raise the colors robbery rodger sailing sailor sea seafaring ship skeletal swashbuckler sword symbol terror voyage walk the plank war watery grave zombie zombie pirate