If it is trained by a wizard it could very well just burn the net. It can fly, turn into a tiny bug, or a wolf. There are few things that can hold a demon, but I hear magic circles are useful. But alas, I propose a rather brutal method. We know it cannot deal with cold iron. What if we impaled it on a spear made entirely of that? This is gruesome but seeing what the goblins did with the glass workers at this point it is eye for an eye.