SDCC 2024: Giancarlo Esposito's Marvel Role in Captain America 4 Revealed

The actor confirmed his villainous MCU role at San Diego Comic-Con's Hall H.

Giancarlo Esposito is slithering into the Marvel Cinematic Universe. The Breaking Bad and The Mandalorian actor has been teasing his unexpected mystery role in Captain America: Brave New World, boarding the Anthony Mackie-fronted Marvel Studios movie as it underwent additional photography in May. The just-released first trailer offered the first look at Esposito's gun-toting villain — along with glimpses of Tim Blake Nelson's Samuel Sterns/the Leader, reprising his role for the first time since 2008's The Incredible Hulk, and Harrison Ford's Thaddeus Ross/Red Hulk — but the secret role has remained under wraps until now.

"When your dreams come true, and you get the call, you walk through the door. I have a great deal of gratitude for all the fans who really had this dream come true, because fan casting has linked us together, and we started to talk," the Emmy-nominated actor said when joining co-stars Mackie, Nelson, and Danny Ramirez on stage at Marvel Studios' San Diego Comic-Con panel in Hall H on Saturday. "Everyone wanted me to be one thing or another thing. There's been a lot of guessing going about who I really am. But to be with this cast — especially Anthony Mackie, who brings it every single time in every way he possibly can — can I say it?"

After looking to Marvel Studios president Kevin Feige for the go-ahead, Esposito confirmed his MCU role: "I am the king of the Serpent Society," the actor announced, revealing his role as Seth Voelker, a.k.a. Sidewinder, leader of the snake-themed supervillain team.

captain-america-4-giancarlo-esposito-sidewinder-serpent-society.jpg

Introduced in 1985's Captain America #310, the Serpent Society has included such serpent supervillains as Anaconda, Cottonmouth, Black Mamba, Cobra, Death Adder, Princess Python, Rattler, Bushmaster, Asp, and Diamondback, a mercenary-turned-ally of the Steve Rogers Captain America.

In the comics, Captain America villains Viper, Cobra, and the Eel formed the short-lived Serpent Squad, which took control of Roxxon Oil corporation president Hugh Jones with the Serpent Crown: an ancient artifact tethered to the snake god Set. Sidewinder eventually reformed the Serpent Squad as the Serpent Society, using his cloak with the power of teleportation to battle Captain America, Elektra, and the X-Men.

"In my other life, I'm a real badass, and you've seen me play a little bit of that intellectually as Gus Fring [in Breaking Bad and Better Call Saul]," Esposito teased in a recent interview. "But when you see me in the MCU, you're going to see a badass, and I'm excited for that. Acting is using every part of your body, your emotions, your senses, your feelings, to portray something. But you haven't seen me use my body in a way that I'll be using it."

The Julius Onah-directed Captain America 4 soars into theaters February 14th, 2025, as part of the MCU Phase 5.

Stay tuned to ComicBook.com's Comic-Con hub for the latest news and updates out of SDCC 2024.