How do you target minipets/untargetable stuff?

I tried asking in q n a forum but no answer. How exactly does people go around targeting that stuff?

Well i was going to return a PM but since this threads here...

You can only target Mini pets through a glitch. It has only happened once to me with my Bone Dragon. I did not do anything to trigger it other than having it out. What causes this glitch i dont know (it just appears randomly as far as i can tell)

Your question was answered in the QA forum, you got five replies where they explained it's just a random bug.