That would be the "Jolly Roger" flag, popularized during the early 1700s by pirates preparing to attack.
the jolly roger
Either skull and cross bones or the pirate flag.
The Jolly Roger
The name given to any pirate flag is "Jolly Roger."
Cranium
cranium
The Jolly Roger or the Death Flag.
The joints between bones of the skull are immovable and called sutures.
Arrgh, that'd be the Jolly Roger, me hearty! The Jolly Roger is the name generally given to all pirate flags. However, the Jolly Roger was a specific flag. It had a black background and was embellished with a skull. Below the skull were two crossbones. Different pirates flew different flags. Pirate flags were used to wage 'Psychological warfare' on their enemies. Pirate flags were designed to threaten, intimidate and spread fear & dread amongst all that encountered the pirate. A pirate flag's history was an important element in building the fearsome reputation of the pirate vessels. Many pirate flags had a red or black background. The flag was often embellished with threatening symbols, such as a skull, bones, skeleton, cutlass and hourglass
The Jolly Roger
The skull and crossbones.
The skull.