Jack Sparrow is known for making a deal with the devil. In exchange for immortality, Jack Sparrow sold his soul to the devil. However, he was not content with being immortal. He wanted to be free from the devil's grasp. So, he devised a plan to trick the devil. He asked the devil to turn him into a sea creature so that he could live in the sea and be free. The devil agreed and turned Jack Sparrow into a sea creature. But Jack Sparrow was not content with this either. He wanted to be human again. So, he tricked the devil again and asked to be turned back into a human. This time, the devil refused. And so, Jack Sparrow is stuck in his current form, cursed to roam the seas forever.