this mod will allow you to conjure a skeletal dragon Enjoy !!
The Hard Roleplay version located to the left of the area (next to where one of the skeletons spawn) where you fight the skeleton Dragon
The Easy version file: spell tome is located in labyrinthian exterior in the area where the wooden mask is located beside the skeleton.
you have to conjure it in a wide open area because the dragon is large and cant be conjured in small areas or indoors.