How to put more accessories on your sims 3 horses?

I'm not sure about animals, and I can't remember which module does this, but it will allow you to place multiple items in the same location. For example in this picture, of a sim that I had created.

The fins and her crown were under the same section, meaning without a mod putting on those two items on my sim would have normally been impossible. But I do know that one of the NRaas Master Controller settings can allow for this.