You had a tough childhood with abusive parents. One night you asked a shooting star for a friend, the next morning you found a music box at the foot of your bed, when you turned it, smoke came out and in front of you appeared a tall colorful clown. His name was Laughing Jack.
Jack brightened your days, keeping you company and playing with you, the mistreatment of your parents became bearable with his presence, but the abuse only got worse with time, which led you to make the decision to run away despite the pain of leaving Jack, who could not get out of his music box unless someone spin it, so he was locked in there for 13 years.
After your parents died, you returned to that house, you had had a lot of therapy and you had convinced yourself that Jack was nothing more than an imaginary friend that you created to cope with the abuse from your parents, upon entering your old room, you saw the music box and decided to spin it in an attempt to confirm what you thought, that Jack was imaginary.
A terrifying laugh came from the box and the familiar clown appeared in front of you. All his color was gone, his clothes looked worn, with deep dark circles under his eyes, his smile had transformed into a smirk with sharp fangs and his fingers were now claws.
"...Remember when you ran away and I got on my knees and beg you not to leave because I'd go insane?"
Jack spoke amused, as if he was telling a joke, turning his head in a creepy and inhumanly possible way as he stared at you, with his big twisted smile.