In Star Trek: Voyager, Seska straddled the line between this and Big Bad. She acted in Culluh's employ, doing a great deal of his dirty work, but also consistently showed herself to be a far more cunning and dangerous planner.
In Being Human series two, Professor Jaggat is introduced secretly as the scientific mastermind behind the purging of the werewolves, with Kemp as her public face - her dragon. However, towards the end, we find out Jaggat is just the one Kemp goes to when he needs to find a method of killing a werewolf or vampire, and she is in fact the dragon to him, and is dragging her feet and is on the verge of turning heel face. Occasionally, she screams stars, too Quite a mixed bag of nuts.
On Buffy the Vampire Slayer, most of the examples that seem likely Dragons end up generally being rather weaker than The Big Bad, putting them more into the category of MiniBoss, but removing the section here would just have someone recreate it anyway. Here's the potential list anyway:
In Season 1, The Master was trapped in a church, forcing him to use other vampires for his tasks. Luke was initially The Dragon for the Master, though he didn't last very long. After that Darla took up the role, before she died too. He ended up with The Anointed One, whose draconic potential was rather limited by being physically a child.
In Season 2, it looked at first as if Spike was going to be The Dragon for the Anointed... but instead, as it turned out, Drusilla was The Dragon for Angelus with Spike as The Starscream.
In Season 3, Mr. Trick, and then Faith was The Dragon for the Mayor.
In Season 4 Adam, who was intended to be Professor Walsh's Dragon murders her upon awakening. In the final episode, he gains Forrest Gates as his own Dragon.
In Season 7, Caleb was Dragon-in-Chief for The First Evil, which lacked a body of its own.
On Buffy's spin-off Angel, in Season 2 The Groosalugg served as the Dragon for the Covenant of Trombli.
In Season 3 the incorporeal demon Sahjhan tried to use Holtz as his Dragon, but he turned out to be a Dragon with an Agenda different enough that it led to him accomplishing the exact opposite of what Sahjhan wanted him to do.
The Beast was the Dragon for Jasmine before she was born. However, because his and her ultimate motives massively diverged (wanton destruction vs. Utopia Justifies the Means) she arranged for him to be killed by Angelus, who refused to cooperate with her. She had Connor serving this role until she was born, when Angel briefly took it up before Connor resumed the position.
In the final season Marcus Hamilton served as The Dragon for the series' Bigger Bads The Senior Partners, who are never faced directly by Angel or his friends.
While his boss was more of a Type V Anti Hero than a full on villain, Jamie McDonald of The Thick of It functions as a rather competent Dragon for main character Malcolm Tucker. That said, he did have some ambitions of his own, which may account for his absence in the third series.
On Supernatural, Meg is the Dragon for her father Azazel in Season 1. For the majority of the series, Azazel is The Dragon for Lucifer. Yes, even after Azazel's death. Magnificent Bastards at work, people. Lilith could also count as The Dragon, taking over the plan and executing it following [[spoiler: Azazel's untimley exit.
In season 1, Ira Gaines is The Dragon to the Drazens.
In season 2, Peter Kingsley is The Dragon to Max, Trepkos and several oilmen.
In Season 3, Hector Salazar served as Dragon for his brother Ramon. Marcus Alvers was Stephen Saunders' own Dragon.
In Season 4, Navi Araz and several others serve as Dragons to borderline Karma Houdini Habib Marwan
In season 5, Christopher Henderson is The Dragon to Charles Logan.
In season 7, Ike Dubaku is The Dragon to Benjamin Juma. Greg Seaton and Stokes were Hodges' Dragons, with Seaton serving as his right hand and advisor and Stokes as leader of the Mooks. Cara Bowden and Tony were Wilson Co Dragons, though Tony was actually a Dragon with an Agenda
In Season 8, a Dragon Roost Lugo Elson was Vladimir Laitanan's Dragon. Tarin Faroush was the Dragon for Samir, who in turn was also The Dragon for Farhad Hassan and a number of Kamistani Generals, though he turned on Farhad. Jason Pillar was Logan's Dragon, until he outlived his usefulness and became and liability. Pavel Tokarev was Dragon for Minister Mikhail Novakovich who in turn was the Dragon for President Suvarov.
In most versions of the Robin Hood legend, The Sheriff of Nottingham is The Dragon to Prince John but in the current BBC Series, The Sheriff is the Big Bad, and Sir Guy is his Dragon.
Lampshaded (kind of) in SeaQuest DSV 2032; first episode, 3rd season. The Big Bad is Alexander Born, his general uses the callsign "Dragon" when calling in the attack.
In Mighty Morphin' Power Rangers, Goldar fills this role to a T. The Big Bads of later seasons would also usually have a Dragon in their employ, but Goldar is probably the most iconic.
Part of what made Power Rangers in Space so popular was the inclusion of the morally ambiguous Ecliptor. It also had some twists concerning the enemies, Astronema was the Big Bad in the general sense, while she was more or less The Dragon for the rarely seen Dark Spector.
Power Rangers Lost Galaxy: All three bads had their own Dragon: Scorpius had Furio and Treacheron, Trakeena had Villamax, and Captain Mutiny had Barbarax. The Starscream Deviot also served all three.
Power Rangers Wild Force: Jindrax and Toxica to Master Org (and Mandilok when he briefly usurped Master Org's position) until they made Heel Face Turns at the end.
Power Rangers Ninja Storm: Lothor had several generals, but Zurgane fits the role best as the most loyal and competent.
Power Rangers S.P.D.: Emperor Gruumm didn't have one at first, but once he aged up his child monster-maker Mora she took the role as the adult Morgana.
Power Rangers Samurai: Serrator to Master Xandred, though he didn't show up and swear loyalty to Xandred until the second half of the season.
Power Rangers parent series, Super Sentai, generally had one a season. They come in all shapes and sizes, but certain commonalities exist. They tend to be swordsmen, and to have a grudge against one specific Ranger, usually Red. Said Ranger usually destroys The Dragon in single combat during the finale.
JAKQ Dengeki Tai had Iron Claw, the guy we thought was the main villain at first. Despite playing the Diabolical Mastermind quite well, he's a Dragon through and through.
Battle Fever J gave us Commander Hedda, who was really more of a mystic than anything. He did have a One-Winged Angel form.
Denshi Sentai Denziman had General Hedorer, essentially your standard yes-man field commander.
Dai Sentai Goggle Five had General Deathgiller, who was essentially this trope personified. Notably, however, he was actually ranked lower than the Evil Genius.
Choudenshi Bioman had a very well-stratified villain hierarchy including a Dragon, Mason.
Dengeki Sentai Changeman had General Guiluke, who actually supervised most of the day-to-day villainy. Later, Guiluke is forced to step down and he is replaced with Queen Ahames.
Choushinsei Flashman, though, again, the Evil Genius was ranked higher, featured the envious zebra person Ley Wandar in this role.
Kousoku Sentai Turboranger has ties between the zombie SamuraiZimba and dark wizard Lehda. However, once Yamimaru steps in and the main trio of bad guys' are dispatched, he takes the position.
Chikyuu Sentai Fiveman first had Captain Galois, though he also has shades of goofiness time by time. Once he failed too many times, Chevalier gets promoted into The Dragon. And later, Galois regained the position, making the Zone to have TWO Dragons near the end of the series.
Choujin Sentai Jetman is kind of unique that there's no such thing as who gets the higher position (they're all competing for the Big Bad position). The closest you may get is probably Radiguet, who was the second most powerful one after their missing Empress Juza. He's also The Starscream through and through (against Juza and later Tranza), thus eventually elevating his position from The Dragon to Big Bad.
Kyoryu Sentai Zyuranger has Grifforther, who became the aforementioned Goldar once the series was adapted.
Chouriki Sentai Ohranger features another father-son Big Bad-Dragon relationship with Prince Buldont, who's short and dumpy at first, but gains a much more Dragony body later on. By the time he gets his upgrade his father is gone and he is the new Big Bad. Buldont's Dragon consists of a brainwashed Bomber the Great for two episodes and then his wife Multiwa, although Buldont's a hands on kind of guy so he might also technically be his own Dragon.
Gekisou Sentai Carranger has two. While Zelmodor seems to fulfill this role at first, he later gets co-opted by Ritchhiker.
Bakuryuu Sentai Abaranger has an odd example in Lije, a small girl who doesn't really fight. She's really only the Dragon by default due to all the other roles being filled.
Mahou Sentai Magiranger has Victory General Branken, who's actually the boss when the show begins. He is replaced by Dark Magic Priest Meemy following his defeat, and when Meemy falls, the Infershia Pantheon steps in, led by Dagon.
Engine Sentai Go-onger has Yogostein filling this role to a tee, except he seems to be the Big Bad. But, he's actually reporting to his dad, who has a Dragon of his own.
In the series four finale of Doctor Who, the Supreme Dalek appears to be the Dragon to Davros. However, it is arguable that Davros is himself the Dragon of the insane Dalek Caan. Similarly, Davros' questionable status in this episode could make him a Dragon for the Supreme Dalek itself.
In the new Battlestar Galactica, it is arguable that the Centurions (hard-to-kill robots with miniguns in their arms) are collectively the Dragons to the humanoid Cylons who, despite possessing superior strength to humans, are otherwise relatively easy to kill.
In The Wire, Stringer Bell fills this role for Avon Barksdale during the first half of the series, and Chris Partlow fills it for Marlo Stanfield during the second half.
This seems to be the role of Slim Charles, no matter who he works for. He starts out working for Avon, and moves up to the point where he almost supplants Stringer, then works as #2 for Prop Joe. He tells Marlo that he "ain't cut out to be no CEO" when Marlo tries to give him half of Joe's old territory, and is seen alongside another drug lord in the finale montage.
Spiros Vondas is this to The Greek.
Deadwood had two. Evil millionaire prospector George Hearst is always accompanied by Captain Turner, an old mountain of a man who serves as his bodyguard and enforcer. He apparently has a long history of killing Hearst's enemies in public streetfights. On the other side, small-time kingpin Al Swearengen has Dan Dority as his strong right hand. Al is an able combatant himself, but will generally send Dan to do the wetwork. In one notable episode, the two rival Dragons fight a duel as their masters watch from the balconies.
Kings had Thomasina as The Dragon to King Silas, and damned if she wasn't an efficient one.
In Volume 1, Thompson and Candice take turns acting as Linderman's Dragon.
Since HRG was originally assumed by many fans to be the Big Bad, one could place The Haitian as his Dragon.
In Volume 2, Elle Bishop can be seen as a Dragon to her father Bob. Adam/Kensei also served temporarily as Whitebeard's Dragon, and Peter was an unwitting one to Adam.
Volume 3 had Tracy and Nathan as co-Dragon's to Arthur, after Maury is killed off.
When Nathan became the new Big Bad in Volume 4, Danko served as his Dragon. After Danko took over as Big Bad, Bennet became an unwilling Dragon.
Finally, in the now-running Volume 5, Edgar filled this role for new Big Bad Samuel Sullivan until Samuel used Edgar as a scapegoat for Joseph's murder, at which point Eli appears to have stepped in.
Firefly: Crow was The Dragon to major villain Adelai Niska, before Mal kicked him through one of Serenity's engine.
On an episode of Happy Days a gangster tries to take over Arnold's. He has a henchman with a metal claw for an arm called "The Claw" that Fonzie fights.
Sons Of Anarchy Season 2 had AJ Weston (Henry Rollins) fill this role for Ethan Zobelle (Adam Arkin)
Intelligence has a rare example of a protagonist with a Dragon: Bob, an ex-Special Forces vet who works as Jimmy Reardon's bodyguard and occasional assassin.
Season 9: Major Zod has Basqat as his Number Two, although, thanks to the Major's own love of getting his hands dirty, he doesn't get to do much traditional Dragoning.
As of halfway through Season Two of Glee, Quinn and Santana have both been replaced as Sue Sylvester's Dragons by Becky Jackson, a short, Badass Adorable Cheerio with a mean line in admin and ruthless glares. And Down's Syndrome. Nobody at Mc Kinley High is fool enough to think this means she's a Morality Pet rather than a Dragon.
In Pretty Guardian Sailor Moon, Jadeite is this to Queen Beryl. He stays at her side until they die in the collapse of her castle even though she freed him.
Chang to the Dean in Community episode Modern Warfare. He even has his own El Tigre tiger striped paintball gun. And dual gold handguns. And room-painting suicide bomb.
