1st appearance of Detective Chimp

1st appearance of the Phantom Stranger, a powerful archmage

1st appearance and origin of Zatanna

[March 2021 - WB is developing a film with Emerald Fennell (Anna Karenina) attached to write]

1st appearance and origin of Deadman

[May 2020 - rumor that Deadman will host an anthology-style HBO Max horror series similar to Tales From The Crypt with a superhero twist]

1st appearance of the Phantom Stranger in the Silver Age

1st appearance and origin of Man-Bat, a scientist whose experiment went awry after combining human and bat DNA to cure his own deafness

First team-up of Batgirl and Robin in a backup story

1st appearance of the Swamp Thing, Alex Olsen

1st appearance and origin of Etrigan the Demon

1st appearance of Morgaine Le Fay, the sister of Madame Xanadu

1st appearance of Randu Singh

1st appearance and origin of the second Swamp Thing, Alec Holland

1st cameo appearance of Anton Arcane

1st appearance of Matt Cable, later becomes the Sandman's raven

1st cameo appearance of the Un-Men

1st appearance of Nathan Ellery, the man who caused the explosion that created Swamp Thing

First ongoing Swamp Thing solo title

1st appearance, cover and origin of Black Orchid

1st appearance of Shade the Changing Man

1st appearance of American Scream

1st appearance of Madame Xanadu, a mystic

[June 2021 - J.J. Abrams’ Bad Robot developing a Madame Xanadu series for HBO Max]

1st full appearance of Dr. Mist, not in DC continuity

1st appearance of I, Vampire aka Andrew Bennett

1st appearance of Mary, Queen of Blood

1st team appearance of the Global Guardians in the mainstream DC universe: Bushmaster, Jack O'Lantern, Little Mermaid, Olympian, Seraph, Rising Sun, Green Fury, Doctor Mist

1st appearance of Amethyst, Princess of Gemworld

Preview, pull-out comic of Amethyst

1st appearance of Dark Opal, the first villain of the series who wants to take control of Gemworld

1st appearance of Carnelian, in the employ of Dark Opal

1st cameo appearance of John Constantine, Hellblazer

⚠ It is widely accepted that this is the first cameo appearance of John Constantine but the character in question is not identified nor does he wear the classic trenchcoat that is seen when Constantine first appears in full, 12 months later, in Swamp Thing #37

Preview of John Constantine from Swamp Thing #37

1st appearance of John Constantine, Hellblazer

[September 2022 - Keanu Reeves will reprise the role of Constantine in a sequel film]

Unofficial team appearance of a Justice League Dark: Blue Devil, Creeper, Man-Bat, Madame Xanadu, Etrigan, Black Orchid, Phantom Stranger

Creeper suggests forming a 'spooky Justice League of America'

1st unofficial team appearance of the Justice League Dark

Death of Giovanni Zatara and Sargon the Sorcerer

1st full appearance of the Great Evil Beast, in the form of darkness

1st full appearance of Timothy Hunter, a boy destined to be the world’s greatest magician

1st appearance of Zauriel, a guardian angel

1st appearance of Frankenstein, the Grant Morrison/Doug Mahnke version of the famous monster

1st appearance of Mindwarp, a man with the ability of astral projection

1st appearance of Pandora

1st team appearance of Justice League Dark: Hellblazer, Shade the Changing Man, Madame Xanadu, Deadman and Zatanna

[Justice League Dark is currently in-development for HBO Max with J.J. Abrams producing]

1st appearance of Nightmare Nurse, when summoned heals supernatural wounds

1st appearance of Sin Eater, the demonic spirit of a serial killer

1st appearance of Doctor Fate, Khalid Nassour

Preview appearance in Convergence Aquaman #2 in an 8-page excerpt of this issue