Put them into the swamp


I just read Black Canaan, graet story. I haven't read any of Howard's pict stories, but I remember that in Across Thunder River there's a spell that turns people into those swamp things. Does this also appear in Conan, or was this taken from Black Canaan?
I took that from Black Canaan, one of my favourite Howard tales. Several spells in Across The Thunder River come from that story.

The best way, I think, to find Howard-style spells is to find them within Howard's stories, even the non-Conan ones.