The Ghosts are named after Modern Warfare 2 character Ghost and even have masks made after the mask Ghost wears. Riley the German shepherd is named after Ghost's real name (Simon Riley), and the honey badger assault rifle is named after an assault vehicle. The least selling game in the Call of Duty series.
Simon Riley earned the moniker "Ghost" due to his exceptional covert prowess. The name encapsulates his stealthy demeanor, enigmatic presence, and formidable battlefield aura. However, that hasn't been officially confirmed either in game by Ghost or by Call of Duty.