Star Wars returned to Marvel Comics in 2015 after a long, historic run at Dark Horse Comics. Before that, Star Wars had been with Marvel from the beginning of the franchise in 1977. Marvel took a chance on the unknown space opera movie with their six-part adaptation. The monthly comic that followed introduced tons of original characters including some villains.
Perhaps no character could top the heroic Jaxxon, a green space rabbit who befriended the Rebels in the early days of the comic, but there were lots of interesting and unusual villains in the original Marvel Comics, some of whom could potentially reemerge in the new canon.
Dani
Dani is like a lot of early Marvel Comics Star Wars villains. They start off bad, but they end up becoming friends or at the least partners with the good guys. Dani was a master thief from the planet of Zeltros. She spent time with Rik Duel and Chihdo, running into the Rebels on numerous adventures that put them at odds with the good guys. She eventually left her life of crime behind and signed up with the Rebellion. She trained with Luke Skywalker and even had a pretty healthy crush on him for a while.
Rik Duel
A number of Star Wars comic books and other novels over the years have tried to recapture the magic of Han Solo in other characters. Dash Rendar from the mid-90s multimedia event Shadows Of The Empire is one, and so is Rik Duel, a thief, scoundrel, and rogue in the model of Han Solo. They were friends and partners in the backstory established in the original Marvel Comics but were always suspicious of each other. After the fall of the Empire, Duel and his gang looted worlds abandoned by the Empire, leading to conflict with Luke Skywalker.
Baron Orman Tagge
Baron Orman Tagge is perhaps the most 70s of all the original Marvel Comics villains with his exaggerated glasses and cape. His glasses actually served a function in the story: he was blinded at some point and the glasses acted as a kind of VISOR that would later be imagined with Geordi La Forge. Tagge was the head of a powerful family and galactic business that supplied the Empire. he tried to muscle Darth Vader out of his spot as The Emperor's right-hand man, which a lot of people have done in the comics and died for doing so, just like he did.
Marvel Jabba The Hutt
The addition of Jabba The Hutt to the Star Wars Special Edition is arguably one of the worst revisions to the saga. The scene is somewhat redundant with the final film and the CGI isn't that great. But it was George Lucas' vision and that scene was actually depicted in the original Marvel adaptation, showing a Jabba that never was.
This Jabba is based not on the actor who played him in the original cut scene, but an alien species later established as Nimbanel. This character was actually modeled on Mosep Binneed, a background character who appeared in the first Star Wars movie.
Crimson Jack
Ice Pirates is a forgotten 1980s comedy that clearly took some cues from Star Wars. The movie might have even taken some cues from Crimson Jack, a scantily clad space pirate who debuted in issue #7 of the Marvel comic. Created by writer Roy Thomas and artist Howard Chaykin, he embodies the early uncertain take on Star Wars in other media. At that point, it was just the one movie. Jack, a pirate master in the Outer Rim, went on to play a role in several stories throughout the original Marvel run.
The Darker
The creators of the original Star Wars comic had a hard time coming up with stories since Lucasfilm limited them in what they could depict. Darth Vader was often off-limits during the period of the original trilogy, so Marvel came up with a lot of new bad guys like The Darker. The Darker first appears in issue #67. He is a creature comprised of the dark energies of the ancient civilization of Arbrans and has a strange reptilian appearance, with two large arms and two tiny ones that he hid under his red cloak.
Tobbi Dala
Tobbi Dala is a Marvel Comics villain who looks a lot like Boba Fett, and that's because he's a Mandalorian warrior as well. Dala hails from an era before the Clone Wars and is part of the Mandalorian Protectors, a group of over two-hundred soldiers fighting to liberate Mandalore from the Empire. He's only one of three Protectors who survived into the Age Of Rebellion. A run-in with Princess Leia casts him as a bad guy and with some doubt about his true motives, but eventually, the truth comes out about these historic warriors.
Fenn Shysa
Fenn Shysa is a Mandalorian just like his childhood friend Tobbi Dala and the two both wear the same armor, intended to be the antecedent of Boba Fett's in the era before the prequels nailed down the Mandalorian culture. Though ostensibly a villain, he fought against the Empire and helped drive them off of his homeworld.
Fenn Shysa is a character who could show up in The Book Of Boba Fett. He died liberating Mandalore, currently under Imperial rule in the canon era of The Mandalorian. In the comics, he asked Boba Fett to take his place as the leader of the Mandalorians after his death, and Boba accepted.
Valance
Berilert Valance is a human bounty hunter who predated Boba Fett by just a bit. Valance first appeared in issue #16 of the original comic in 1978, written by Archie Goodwin and drawn by Walt Simonson. Valance is on the trail of Luke Skywalker but gets injured. He becomes a half-cyborg as the series continues. Valance was revisited for the current Marvel Star Wars comics and his background was fleshed out a great deal more, connecting him directly to the past of Han Solo explored in Solo: A Star Wars Story.
Lumiya
Lumiya is likely the most successful of the Marvel Comics villains and a Sith Lord who could conceivably reappear in Disney content going forward. Shira Brie was an Imperial secret agent who infiltrated the Rebellion and spied on Luke Skywalker. She was injured and turned into a half-cyborg, not unlike Darth Vader. She was reborn as Lymiya, distinctive among other villains with her light-whip. Lumiya fought Luke Skywalker on a number of occasions in the comics.