A new villainous organization called the Serpent Society is making its Marvel Cinematic Universe debut in Captain America: Brave New World. They’re a group of snake-themed bad guys led by Giancarlo Esposito’s Sidewinder who have a long and colorful history in Marvel Comics. In 2015, MCU boss Kevin Feige jokingly revealed the title of Captain America 3 to be Captain America: Serpent Society before showing it was actually going to be Captain America: Civil War. But now it’s no laughing matter. The Serpent Society are making their MCU debut for real. Here’s everything you need to know about Sidewinder and the Serpent Society before Captain America 4 slithers into theaters on February 14, 2025.

Giancarlo Esposito as Sidewinder in Captain America: Brave New World.
Marvel Studios/Marvel Comics

What Is the Serpent Society? 

Since their comic book debut, the Serpent Society’s group of snake-themed bad guys have made a striking impression on the Marvel Universe. They possess monstrous appearances and a variety of squeezing, paralyzing, and poisoning superpowers. The villainous Seth Voelker, aka Sidewinder, created the Serpent Society to be more than just a group of snake-themed evil-doers. He structured the group like a trade union and made it far more organized than your standard gang of goons. The society offered profit sharing, health insurance, and kept its members out of prison thanks to Sidewinder’s teleportation ability. That’s what has made them such an enduring menace to Captain America and Marvel’s other heroes over the years. They’ve been referred to as the “Avengers of the Underworld” and have been hired as muscle by the Kingpin, the mafia, and HYDRA.

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The Serpent Society’s Comic Origins and Evolution

Before we get to the origins of the Serpent Society, we have to talk about its predecessor, the Serpent Squad. In 1972’s Captain America #163, the villain Viper created the Serpent Squad to take revenge on Captain America and the Falcon for imprisoning his criminal brother, the Eel. (Yes, eels aren’t snakes, but they’re close enough to fit the theme so we give this a pass.) They were aided by the Cobra who was previously a villain to Thor. 

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After their initial defeat, the team would reform with new snake-themed members joining over the years. They were little more than a group of disgruntled criminals in snake costumes. The team became much more than that when their number later merged into the Serpent Society. They made their big debut in 1985’s Captain America #310. Under the leadership of Sidewinder they became a formidable evil organization resembling a labor union. In the 2014 relaunch of Captain America in which former Falcon Sam Wilson takes up Steve Rogers’ shield, rebranded the Serpent Society. A new Viper (previously Madame Hydra) dubbed the team Serpent Solutions. This iteration offered their services to big corporations to do their dirty work and used legal loopholes to absolve them of any wrongdoing. 

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Sidewinder’s Origins

At San Diego Comic-Con 2024, actor Giancarlo Esposito revealed that his Captain America: Brave New World character is Seth Voelker, better known as Sidewinder. In the comics, Seth Voelker started off as an unassuming economics professor from Kenosha, Wisconsin. His life took an unexpected turn when he failed to make tenure, taking a job at the shady Roxxon Oil Company. He discovered the corporation’s illegal activities and volunteered to undergo a mutagenic experiment that changed his physiology into that of a snake.

Sidewinder’s first comic book appearance came in 1980’s Marvel Two-in-One #64. Roxxon hired him to launch a surprise attack on the Fantastic Four’s Thing and his undersea ally Triton in order to steal a mystic artifact called the Serpent Crown. After a stint working for Roxxon, Sidewinder used his business savvy and strategic skills to start and lead his own criminal organization full of fellow snake-like baddies, the Serpent Society. 

Sidewinder’s Powers and Abilities

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Even though Voelkner transformed into a snake-man, the extreme change to his body didn’t grant him any super powers. Sidewinder’s powers come from the equipment given to him by Roxxon. A technologically-advanced cape grants Sidewinder the ability to teleport. His bullet-proof armor gives him durability during combat. Sidewinder made great use of his teleportation ability by continually rescuing his teammates from incarceration. Voelkner’s key traits are his shrewd intelligence and his ability as a tactician, which he used to elevate the Serpent Society from a rag-tag group of criminals to an enduring trade union of supervillains.

Other Sidewinders

Seth Voelker is the original Sidewinder, but as is tradition in Marvel comics, other characters have picked up the mantle over the years. One successor was a flash-in-the-pan who made his debut and died in the same issue while trying to infiltrate S.H.I.E.L.D. We never even learned his real name. The other Sidewinder is Gregory Bryan, who filled the teleporter role in the Serpent Society’s ranks after the original Sidewinder retired. He never took to the position of leader like Voelker. Instead he worked for Viper when she rebranded the business as Serpent Solutions.

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Members of the Serpent Society

As one would expect, the Serpent Society’s roster includes many snake-themed villains. Each member’s powers came from their snake of choice. The original team featured the teleporting Sidewinder, superstrong Anaconda, venom-blasting Asp, telepathic Black Mamba, cybernetic Bushmaster, speedy King Cobra, bionic-jawed Cottonmouth, poisonous Death Adder, acrobatic Diamondback, shock-wave emitting Rattler, and electrifying Princess Python. It’s worth noting that Sidewinder’s love interest was fellow member Tanya Sealy, aka Black Mamba. Viper later joined the society with her crew including Black Racer, Boomslang, Coachwhip, Copperhead, Fer-de-Lance, Puff Adder, Rock Python, and Slither. 

The Serpent Society’s Beef with Captain America

The Serpent Squad started out as Captain America villains with a grudge against the Sentinel of Liberty. Though the organization had gone on to become a threat to the greater Marvel Universe, things were always personal when it came to Cap. Sidewinder often found his group in conflict with Captain America, but when the ever-ambitious Viper staged a coup and overthrew Sidewinder, he found himself with nowhere else to turn. Sidewinder decided to team up with Steve Rogers (then known as the Captain) to strike back at Viper. After the whole Viper debacle resolved, Sidewinder retired from the Serpent Society and accepted Cap’s help to raise money to treat his cancer-stricken daughter. 

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Serpent Solutions was the first big threat that Sam Wilson faced when he became Captain America. Later in the controversial 2016 Captain America storyline where Steve Rogers declared his allegiance to HYDRA, Serpent Solutions played a part in HYDRA’s rise to power and takeover of the planet. This all happens in the comic event series Secret Empire.

Giancarlo Esposito’s New Take on Sidewinder

“I can finally unleash it. I am the King of the Serpent Society; I am Sidewinder!” Giancarlo Esposito revealed to a crowd of Marvel fans at San Diego-Comic Con 2024. He appears to be playing a new version of Sidewinder that’s quite different from how he’s depicted in the comics. Comic book fans have pointed out that Esposito’s orange jacket collar evokes his snakey comic book costume. But that’s as snake-like as Esposito gets, at least from what we’ve seen so far from the trailers for Captain America: Brave New World.

Esposito isn’t wearing any prosthetics, so he appears as a normal man rather than an anthropomorphic snake. That’s not to say Esposito won’t eventually transform to something a bit more scaly later in the movie. The mad scientist the Leader, played by the returning Tim Blake Nelson from The Incredible Hulk, certainly has the skills to make that happen. We already know Captain America: Brave New World will see Harrison Ford’s President Ross transform into the Red Hulk. So who’s to say Sidewinder won’t turn into a snake-man? 

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Sidewinder appears to be more hands-on in the MCU than his comic book counterpart. “I have the ability in this to show not only my brain but to show my physicality. I have the tools; I know how to use them. You’ve never seen me this way,” Esposito told Total Film. Esposito’s character uses guns and knives out in the field, whereas the comics version of Sidewinder tended to stay behind plotting from Serpent Society headquarters and only pop in and out of danger with his teleportation cloak. Curiously, Esposito referred to his character as the “King” of the Serpent Society, which isn’t a title the character ever adopted in the comics. Perhaps it’s an apt moniker for a snake villain because it evokes the deadly king cobra.