Is this ow into black magic or the deep dark side of life? Skulls and crossbones for a child? That's just sick. I'd like to know where your xh was when this was all taking place.
I would definitely raise the issue, in a very calm voice, when he picks them up for the next visit. It's too bad you didn't take photos so that you could point out just had awful they looked.
Let's hope that next time, she won't come home w/that mess.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.