This achievement requires you to get the four Jack Sparrow characters:
Jack Sparrow
Jack Sparrow Waistcoat
Jack Sparrow Chief
Jack Sparrow Cursed
The first three you will get naturally through story progression as you have to play as them in a particular level and you will get them at the end of the level. The tricky part is the Cursed Jack, which is unlocked to buy in the hub after level 1-5, Isla De Muerta. From personal experience, because I had a really hard time finding him, Cursed Jack will only show up if you are not playing as another Jack character, and he will almost always be in the main part of the hub with mission select area. Also there is another Jack which is unimportant to the achievement, but is pretty cool, he's like a theme park version and whenever he's equipped he'll play the music from the ride, he can only be unlocked using this code - VDJSPW.