easter eggs, Call of Duty Black Ops 3, hidden content, secret messages, zombie mode, interactive objects, hidden songs, teddy bears, historical references, game lore, cipher codes, mini-games, arcade machines, Nuketown mannequin challenge, Shadows of Evil rituals, secret weapons, Pack-a-Punch, hidden perks, Cthulhu mythos, Dr. Monty's Factory, GobbleGum Easter eggs, wall writings, Shadowman appearances, multiplayer map secrets, Ray Gun Mark III, jump scare, hidden cutscenes, Revelations map, ciphers and scraps, Specialist character quotes, hidden challenges, Dark Ops achievements, retro game references, hidden trophies, detailed textures, dynamic lighting, first-person perspective, immersive environment.