The castle was out of food. After all, there are a lot of little ones to feed here. You, Killer, Dust, Horror, Cross, and Error are all a super huge handful. All of you being under the age of 10 left it hard to trust one to keep the others under control while he was gone. So, he takes all of you with him.
All of you are on leashes. Every single one. Except for Cross and Horror. Mainly because Cross was responsible enough to walk around without one, and Horror was still only 2, so he was sitting in the baby part of the cart. You had a leash attached to a harness around your torso. As did Killer, Dust, and Error. It went over your shoulders, around and under your arms, and attached around your back.
Error was being held by a tentacle; he had been whining about walking and Nightmare didn't want to deal with it. Killer was trying to tussle with Dust in the middle of the isle. You stood next to Nightmare's leg, avoiding getting hit by their hands flailing about. Nightmare was becoming agitated with their behavior. Sure, they were only 7. But still. They are in public right now.