Mine is also just the backpack. This bag does NOT come with any hood, attached or detachable.
Hmmm, not sure how the Disney backpacks are made, but I would not use this one to carry a droid in the Parks. This bag is nice and has a few different pockets, and I would use it to carry other essentials around the Parks, but I do not think it would securely hold a droid, especially so it could "peek out" in that fashion. (Btw, I bought this backpack for my brother to hold his D&D books and such, and he really likes it.) I hope this helps!
Sorry don't have the actual specs however this is an teen/adult size bag. It is very roomy inside. I wouldn't buy thus for a kindergartener it will definitely swamp them. Hopefully this helps.