WARNING: Spoilers for Moon Knight.
Moon Knight is still early in its run on Disney+ but the series has already introduced a number of major characters from Moon Knight comic book lore like Khonshu and Ammit. Though it is early, there are a number of major comic book characters who have yet to appear in the MCU and don't appear as though they might, at least in the immediate future of the series.
Major Moon Knight comic book characters not yet in the MCU include major villains like Shadow Knight and Moon Shade. They also include critical allies who help Moon Knight in the comics. One of them, Frenchie DuChamp, has been teased in the MCU but other major associates remain. One of the most significant Moon Knight personalities also remains unaccounted for, at least for the moment.
Shadow Knight
Shadow Knight is one of the most powerful villains in Moon Knight lore and a key figure missing from the MCU. Randall Spector is the brother of Marc Spector and a one-time ally who turned into one of his most dangerous and bitter enemies.
While it's early, it's likely he will appear and may even appear within the series. The series has hinted at a third personality for Moon Knight but that could actually be a separate person, perhaps his brother Randall who is secretly helping him.
Black Spectre
Black Spectre is one of Moon Knight's major villains from his first solo title, first appearing in Moon Knight #25. This armored figure is a dark inversion of Moon Knight who was inspired by Marc Spector, making him a major character absent from the MCU.
Black Spectre could be a potential villain in the MCU at some point, especially as he connections to other Moon Knight characters He joined forces with Mephisto and Bushman to resurrect Seth, a major Egyptian deity and villain in Marvel Comics.
The Shadow Cabinet
The Shadow Cabinet is a major group of supporting players from the Moon Knight comics who provide Marc Spector material and logistical support, making them very key Moon Knight-related characters who haven't yet appeared in the MCU.
They're comprised of a group of characters including informants from around the world who Moon Knight relies on for information and insight into the operations and movements of international criminals and villains.
White Dragon
Moon Knight has faced many powerful villains in Marvel Comics and one of the first he faced off against was White Dragon. White Dragon is an expert martial artist steeped in the criminal underworld of the Marvel Universe that Moon Knight is closely connected to.
Moon Knight joined forces with Spider-Man in Marvel Team-Up #144 to take on White Dragon, an early and significant opponent yet to appear in the MCU but may as other characters like Daredevil and Kingpin now emerge.
The Sun King
The Sun King was the subject of a lot of speculation ahead of the series, possibly as the main villain. That hasn't come to be, leaving the Sun King one of the biggest Moon Knight characters not yet in the MCU. This powerful figure first appeared in 2017, during Jeff Lemire's run on the title.
The Sun King first appears as Patient 88 in the same mental health facility that Marc Spector is in, but reveals himself to be a powerful villain who derives his immense pyrokinetic powers from the Egyptian god Amon Ra.
Seth The Immortal
Episode three of Moon Knight introduced five of nine members of the Ennead, the Egyptian pantheon of deities. One notable figure absent from that gathering was Seth the Immortal, one of the most powerful members of the Heliopolis gods in Marvel Comics.
Seth is an antagonist in the comics who challenges the other gods and in a fantastic storyline beginning in Thor #239 that introduces the pantheon in large measure, attempts to destroy his entire family in a bid to rule alone.
Moon Shade
Moon Shade is one of the most powerful versions of Moon Knight in the comics and one of the character's most powerful villains, making him a major character not yet in the MCU. He is likely at some point, especially with the multiverse playing such a major role in the franchise.
Moon Shade was created by Magus, the alternate evil version of Adam Warlock, and went through the multiverse consuming the life force of other Moon Knight variants in Marc Spector, Moon Knight #42, a key issue from the early 90s.
The Committee
The Committee played a major role in the early career of Moon Knight in Marvel Comics. This shadowy organization manipulated Moon Knight into attacking Werewolf By Night in this first appearance in the comics as well as Spider-Man not too long after.
Their absence from the MCU is notable, but they could emerge as the series progresses. With Werewolf By Night coming to the MCU in the Marvel Studios Halloween Special, it's possible this cabal could manifest as villains in the MCU. They may even involve mysterious characters already active in live-action, like The Contessa.
Jake Lockley
In the comics, Moon Knight has numerous different personalities. One of the most significant and powerful Moon Knight personalities is Jake Lockley, who in the Marvel Universe is a cab driver with his finger on the pulse of the criminal underworld.
Lockley cultivated a network of informants who provided Moon Knight with intelligence that he was able to act on against criminal enterprises and supervillains. There are hints that Lockely is one of Moon Knight's personalities in the MCU, but he hasn't appeared.
Marlene Alraune
Marlene Alraune is perhaps the biggest supporting character in the Moon Knight mythos who doesn't appear to be coming to the MCU. She is Marc Spector's love interest in the comics and a major player in his life going back to his origin.
While she doesn't seem to be on the horizon in the MCU, a version of her may already be in the Moon Knight series. The character of Layla has some biographical elements of Marlene, specifically being an archeologist whose father was killed in tragic circumstances.