Howard purists may hate every word I am about to say. While I will always agree that Robert E. Howard’s stories were the best of the Conan canon (he wrote some potboilers too), I do have some favs amongst the Lin Carter and L. Sprague de Camp pastiches. One such tale is “The Curse of the Monolith”. The story first appeared in the obscure magazine Worlds of Fantasy #1 (1968) as “Conan and the Cenotaph” alongside a John Jakes’ Brak the Barbarian tale, a Robert E. Howard historical bit and plenty of Science Fiction. The story received an illustration by Jack Gaughan.
The plot has Conan falling for a trap set by Duke Feng (who wouldn’t trust anyone with that name?) Conan is acting as ambassador for King Yildiz of Turan. Feng lures him to the sight of the cenotaph or monolith (take your pick) knowing that the obelisk (there’s another one) is magnetic. Conan is dressed in mail and is soon trapped. In the best evil Bond villain-style, Feng doesn’t just cut his throat but explains his evil machinations. Feng watches as the monster that lurks at the top of the monolith makes its presence known:
“…The rising half moon shone on and through an amorphous thing, which squatted obscenely on the summit of the column. I t was like a huge lump of quivering, semitranslucent jelly…The moonlight glistened wetly upon it as it beat like a huge, living heart…The had changed, and a vagrant down-draft wafted a sickening stench to Conan’s nostrils. Now he knew why the bones at the base of the shaft bore that oddly eaten appearance. With a dread that almost unmanned him, he understood that the jellylike thing exuded a digestive fluid, by means of which it consumed its prey.
The monster is awakened by the use of shrill pipes, not unlike the slug monster in Howard’s “The Valley of the Worm” (Weird Tales, February 1934). Carter was always finding ways to link the Conan stories with the Cthulhu Mythos of H. P. Lovecraft. Only Conan’s massive strength will see him free of the megalith (yup, another one) and avenge himself on Feng.
Which is all after the fact, because I didn’t encounter this pastiche in written form. I first experienced it as a comic book. The Savage Sword of Conan #33 (September 1978) bears a wonderful Norem painting of Conan struggling against the magnetic menhir (wow, another one!) while the bubbling slime begins its descent. That was my first take on this story. It was followed up by a Roy Thomas adaptation with artwork by the non-John (Buscema) team of Gene Colan and Pablos Marcus. This was Gene’s only Conan gig though Pablo went onto do several more. (As I said elsewhere I always enjoy seeing how really good artists who are different than John 
Buscema work the Conan material.) Gene doesn’t stray too far from the Buscema mold but I enjoyed it anyway. His portrayal of Feng might be considered a little racist but let’s be honest, the whole story smacks of Fu Manchu. Lin Carter is getting his Sax Rohmer on big-time with the whole monolith trap thing.
Anyway, this story is one of a handful of pastiches I consider worthy of being part of Conan’s story, along with “The Thing in the Crypt”, “The Lair of the Ice Worm”, and the quartet of Conan of Aquilonia pieces. These picks may not be based on any literary merit, more likely just on nostalgic memories of a young man who loved the Sword & Sorcery genre more than any other. Comics, books, and games, this time ended when the movie Conan the Barbarian showed up (1982) but I can recall that golden decade of heroic fantasy that was 1968 to 1978.