Graves collars Credence with a magical collar only they can feel. When Graves touches his wand to it it appears glimmering and golden, tight and nearly choking around Credence's throat

"Have you ever had a pet?" Mr Graves asks, stroking his hair.

"Ma won't allow it."

"Well, some people take very good care of their pets. Others--" he tugs at thick strands at Credence'a nape, "--don't."