Without looking it up, I think morph has two origins, but you're speaking of the one meaning, "form." I see nothing wrong wish using the term as you have done. As for the other origin, babies and toddlers are at their best when Morpheus visits them!
I see nothing wrong wish using the term as you have done.
For the record, someone else used that term (about my sweet grandchild), and I thought it was wrong - or, at least, like Bob, I'd not use it that way. I thought the definition was more like this.