Assassin’s Creed 4 Black Flag has many Easter Eggs. While roaming the seas with Edward you can find some quite interesting details added to the game. From two guys trapped in a well and asking for help (the voice of one of them is strangely familiar, no?), to the weapon collection in Abstergo and a battle between a whale and an octopus you can admire. Once you’re out of the animus, you can find some Watch Dogs references and that’s pretty cool too, I’d say.
Here are some of the easter eggs you can find in AC 4 Black Flag. The video below will show you where they are exactly and what exactly you have to do to find them.