Masters of Horror Source Material

Stories adapted for the Showtime series created by Mick Garris, which lasted two seasons in 2005-06. "Bokkee, Kyotee" (which I think means "really scary") is a novel which unfortunately has never been translated from the Japanese. (Fun fact: the author, Shimako Iwai, played a major role in "Imprint," the episode based on her book.) "Chocolate" is a story by Mick Garris himself—a story much better than the episode, in my opinion. James Tiptree, Jr., is a pen name for Alice (Bradley) Shelton, aka "Raccoona Sheldon." In addition to "Haeckel's Tale," Clive Barker also wrote an original screen treatment for the episode "Valerie on the Stairs." "Jenifer" is a comic by Bruce Jones and Berni Wrightson that appeared in the July 1974 issue of the comic "Creepy."
You can find sources for the stories on isfdb.org. Enjoy!