They’re DEMONS want to possess you.
They are NOT Alienstransform themselves.
The Fallen Angels transform into Ships, UFO, and other Creatures in our Dimension. They cannot always maintain their forms, so they morph from UFOs to a Dragon Looking creature, that cannot maintain its form in our Dimension, but they do not want to go back to their own Dimension. You can throw a Nuclear Warhead at them and it is like throwing sticks at them.
The fallen angels appear as “balls” of light, and then dissipate.