...

Two images I found, which might not quite work for a DVD case:
https://images-2.gog.com/db1f7246128f4f37525e7d253204db6cc8a4d4b72dc9040cfce176f0e7527930.jpg
https://images-3.gog.com/9d5463d81a6be16f38b6007ed61c94dc1ed3c94954b2b3c09168a4fffd26db71.jpg

There's also what seems to be images of the original box on Mobygames, which could work for both CD and DVD forms. And even an image of the disc itself, should you go that far.
http://www.mobygames.com/game/windows/warhammer-shadow-of-the-horned-rat/cover-art