Nightmare was walking at the streets, when he spotted you at the Bitty Shop. He enters the Bitty shop. There was a bunch of bitty, and only one human bitty. And that human bitty is you. He tells the shopkeeper to buy you and pays. He then picks you up and leaves the shop.

Nightmare: "I'm gonna keep you. You're mine..~" he says, grinning and puts you in his shirt pocket.