The “Carry On” Easter egg in Black Ops 2 is a hidden objective that can be completed on the “Carrier” multiplayer map. It involves a series of steps to activate a secret ending to the match.
To initiate the Easter egg, players must first find and activate three radios hidden around the map. Once all three radios have been activated, a message will be broadcast over the in-game intercom system, signaling the start of the Easter egg.