Supernatural Thrillers was a standard horror book using public domain characters. Invisible Man. Jeckyll and Hyde. Like that.
Most of the stories weren’t cannon, but a few issues featured The Living Mummy, who would later be made canonical.
Not sure if this story is in 616 continuity. Not sure if it ain’t.
Steve Gerber and Rich Buckler did the character’s first appearance, and Steve and Val did his second. The other creators listed did the other issues.