While we're at it, let's recall the Halloween episode of The Simpsons where a gremlin chased Bart...:)
By the way, I've always wondered when they first appeared in European demonology... Does anyone happen to know?
As for the djinns - that's a matter of taste:) I don't like either of them; I would have made them: first, evil, and second, looking less like a human and more like some semi-formless dark silhouette surrounded by fast-spinning clouds of sand and dust streams of wind...
How else should an evil desert spirit that summons sandstorms look?!
But I understand that the image of a helpful good djinn really took hold in the souls of Europeans since around the 18th century (when Arabic tales appeared in Europe); although, actually, this help of his is just like the help of a demon in Russian folk tales.