Dumbledore. He got it from James, Harry's father.
It is a cloak that makes you invisible when you wear it. It's one of the three Deathly Hallows.
He recieves it in the first movie/book, Harry Potter and the Sorcerer's(Philosopher's) Stone.
you can get it from websites or from other dressing up shops
He received it at Christmas in his first year at Hogwarts from the headmaster Albus Dumbledore (although he didn't know it at the time). Dumbledore had borrowed it when the Potters were killed and...