1:4 This is Jason Blood, the Demon Etrigan.

The Alan Moore Songbook

2:1 This store appears again in ST Annual #5. Let's look at the signs:
"Gris Gris" are voodoo charms.
The comic book rack includes underground comics like ZAP COMICS (by Robert Crumb in the 1960's) and SKULL (both of which Moore mentioned in "Too Avant Guarde For The Mafia" in INFINITY #7 and 8.) and and FREAK BROTHERS (a drug-related early 1970's book from Gilbert Shelton and Dave Sheridan's RipOff Press). HAROLD HEAD by Rand Holmes, was published in 1973 by Last Gasp. Some of these comics are also seen in Chester's home in #43.
"The Sinister Ducks" is the name of a band ST author Alan Moore was in. They did a song called "March of the Sinister Ducks". Visit this link for a flash animation of the song. The 1983 7" single included the 8-page comic book "Old Gangsters Never Die" with art by Lloyd Thatcher. A 1983 issue of the comic book "Critters" from Fanatagraphics Books included a flexi-disk recording of their music. Read other song lyrics in Alan Moore's Songbook.
Paul Evans of the Alan Moore Transcription Project identifies more of the books:

FAT FREDDY'S (CAT) (a spin-off of the FREAK BROTHERS) and DOG BABY(?). Also I think I see "Fantagra-" (see AMAZING HEROES #39: Moore "appeared gratified by my enthusiastic response to his work and in return complimented us on Fantagraphics' various projects.")

2:2 The top poster is a painting depicting hell, by the late 15th century surrealist Hieronymous Bosch. It is part of a triptych called The Garden of Earthly Delights. Issue #53 is also titled "The Garden of Earthly Delights". Bosch's creature designs are influential in the art of ANNUAL #2.

About the beer poster: S. Clay Wilson's Checkered Demon character drank Tree Frog Beer. Learn more about him in the notes for issue #77.

Goya's portrait: Note the cat, which sits by, doing nothing.

2:3 Among Francisco Goya's most famous pictures is this self-portrait, The Sleep of Reason Produces Monsters, from a series of engravings entitled "The Caprices", 1799.

The tarot card is the Devil because Jason is a demon.

Bob Smith, another visitor to this site, identified the poster on the right showing the demon Baal. This demon also appears in SWAMP THING ANNUAL #2 page 33.

In Comics Journal #106, Moore told of an letter they received from an an angry reader who was offended that the man in the "occult shop" was drawn to look like Jesus Christ. In actuality, the drawing was based on Alan Moore!

Baal, from Collin de Plancy's 1818 Dictionary Infernal

6:6 Steve Bissette says that he based his drawing of Deanna on a friend of his.

6:7 What is the logo with the 2 wolves? For info on the names Kalnick, Nancy, Ruiz and Vargus, see comment at bottom.

7:4 Children With Emerald Eyes (1977) is a real book by Mira Rothenberg about children diagnosed with schizophrenia.

We see here a book that seems to be titled Dead Things Eat First. The closest guess I can make is that it's a reference to the real book Eat First--You Don't Know What They'll Give You, (The Adventures of an Immigrant Family and Their Feminist Daughter), the memoirs of Sonia Pressman Fuentes.

9:2 The man's shirt says "Beer drinkers do it with gusto". In the 1960's, television beer commercials were noted for their aggressiveness. Decades after, Americans who lived in that era remember how the slogan for Schlitz beer “Grab for all the gusto you can get” made the word "gusto" synonymous with their product.

10:1 Link from 9:6 "How did you know that Selena was the name of"-"My wife..."

12:2 "The Third Eye" is the same store from which Jason Blood bought the Goya poster.

12:6 Chris Kalnick tells me that he was the visual model for Paul's father. (See comment at bottom.)

Constantine's first appearance!

21:2 Although #37 is credited as being the first appearance of John Constantine, here he is! (Panel at right) Artist Steve Bissette says that he and inker John Totleben told writer Alan Moore that they would continue to draw this guy who looked like Sting into the book, so Alan used him to create the character of Constantine. Like Constantine, Sting has had experiences in Newcastle. Constantine's next published appearance was actually in a Swamp Thing advertisement in DC Sampler #3.

COMMENT: Re: page 6, panel 7 - Several children's drawings are shown with signatures. Chris "Kalnick" is the writer/artist of self-published comics like NON and DEPTHCHARGE DIGEST. When I asked him, he had this to say:

"Yeah... I'm the same Kalnick that is mentioned in Swampthing #25. As a matter of fact, that's me getting mauled by the little fear-monkey on pages 12 and 13. I guess there's a little story behind it. I went to the Kubert School with Totleben and Bissette, and Johnny and I were in the same class and close for a while. I was a bit spaced out in metaphysics and I guess Johnny thought it would be appropriate to throw me into that issue. It was common for those guys to do that type of thing. As a matter of fact... M.Vargus, Grimes, and Ruiz were also Kubert students. I believe Nancy was Bissette's ex-wife(all on page 7, panel 4). And that's about all I can remember from that time.

You'd have to contact John and see if he can remember anything else about it."

"The usage of our old QB school friend, Chris Kalnick as a character in issue #25 was Bissette's idea, not mine. Of course, I went along with the joke since any opportunity to stick a good-natured elbow to the ribs of an old bud in a comic book story should not be passed by! I don't know that this had anything to do with Kalnick's metaphysical interests, though."

COMMENT: The original printing of this issue included a half-page ad for the reinvigorated SWAMP THING comic book series. It describes Swampy finding out his true origin "...and he doesn't like it. He doesn't like it at all."

COMMENT: View the original printing plate for this issue's cover at Steve Bissette's blogspot.

COMMENT: In 1987, DC Comics collected/reprinted issues 21-27 in a trade book titled "Saga of the Swamp Thing". In 2009, DC Comics collected/reprinted issues 20-27 in a hardcover titled (again) "Saga of the Swamp Thing". This was the first time that issue issue #20 was reprinted in the United States, but the caption on the final page of issue #24 was left out!

COMMENT: This issue was reprinted in black & white as ESSENTIAL VERTIGO: SWAMP THING #5 January 1997.