The front cover painting is by Bill Willingham, and it’s one of my favorites. The action rides the lightning, so to speak. The spell cast by our beautiful, crimson-clad sorcerer ties her, the hero, to the undead villain. The book and the broken staff, framed in the flash, tell us that our magic user was hurriedly memorizing her spell when attacked by the skeleton. That’s my interpretation, anyway.
The castle is parallel to the book and the staff, menaced by lightning of a more natural kind—or maybe not, as the bolts seem weirdly focused on the mysterious edifice. At the same time, the purple clouds on the horizon contrast the town with the bright blue of Bone Hill.
Back cover art is by Erol Otus, a master of atmosphere. The colors here are subterranean, dank. As the dragon drags out of the cave its colors shift from green to an unhealthy pallid blue.
You’ll find Grognardia’s positive review of the module here.
2 Warps to Neptune 
Oh man I would love to have back my original modules!
I think the skeleton is artistic license. I believe this is some sort of creature that is being zapped, and its skeleton is showing through much like a cartoon character being electrocuted.
Hobgoblin: You can download many of them for free. Click on my “D&D Module” category for links. (Also, your name refers to ASM #238, the first appearance of Hobgoblin. The question is: do you have the book with the Tatooz intact?)
Anon: Good damn point. The “skeleton” does appear to have flesh. This particular module is not available online, unfortunately, so I’m not sure what species of evil lurks atop Bone Hill…
No I do not. It is just my blogger name. Also I love those first early issues of the Hobgoblin!
I do too. I haven’t talked a lot about comics, but I’ll work on that…