Morale Patches, or simply patches. These are informal patches that became popular during the military campaigns in Iraq and Afghanistan among the American military. Unlike insignia and military chevrons, patches do not carry any official information, but only indicate the owner's sense of humor.
The Wild Hunt is a squadron of ghostly horsemen that gallop through the sky and are considered a sign of approaching war.
The patch design was inspired by the game "The Witcher 3: Wild Hunt".