13 Actors Who Guest Starred on 'Buffy the Vampire Slayer' Before They Were Famous (PHOTOS)

Carmine Giovinazzo, Season 1, "Welcome to the Hellmouth"Buffy the Vampire Slayer upended conventions from its very first scene, when a leather jacket-wearing bad boy breaks into Sunnydale High School with a timid blonde. Turns out she’s the vampire, and Carmine Giovinazzo, who later played Det. Danny Messer through the entire nine-season run of CSI: NY, has the distinction of being Buffy’s first victim.

Eric Balfour, Season 1, "Welcome to the Hellmouth," "The Harvest"

Jesse McNally is not quite the Ned Stark of Buffy, but you could make the case. Xander’s best friend and fellow loser, Jesse could of been a Scooby but was kidnapped by acolytes of the Master and turned into a vampire. At least he got to dance with Cordelia before Xander accidentally staked him in the show’s second episode!

Balfour starred in a string of quickly canceled series but did make an impression as Claire’s boyfriend Gabe in Six Feet Under, CTU staffer Milo Pressman on 24, and smuggler Duke Crocker on Haven.

Clea DuVall, Season 1, "Out of Mind, Out of Sight"

Marcie Ross is a Sunnydale student so used to being ignored that she begins to vanish, and then uses her powers to exact revenge on the popular crowd. In a classic twist ending, Buffy captures her and turns her over to the FBI&emdash;which promptly enrolls her in a training school for government assassins.

Clea DuVall’s off-kilter energy found a home in the cult drama Carnivale and American Horror Story: Asylum, and she now plays a Secret Service agent in love with Selina Meyer’s daughter on Veep.

John Hawkes, Season 2, "I Only Have Eyes For You"

One of the more twisty Buffy episodes, a doomed romance between a male student and a young female teacher in the 1950s is replayed in the present by possessed Sunnydale students and staffers, including John Hawkes as a janitor channeling the young student who shoots a teacher before being tackled by Giles. (Later Buffy and Angelus take on the roles of the lovers, but with the gender roles reversed.)

Hawkes went on to play storekeeper Sol Star in Deadwood and earned an Oscar nomination for Winter’s Bone and a Golden Globe nod for The Sessions.

Wentworth Miller, Season 2, "Go Fish"

This episode may be best remembered for how well Xander filled out his Speedo as the newest member of Sunnydale’s swim team. But it also marked future Prison Break and DC’s Legends of Tomorrow star Wentworth Miller’s showbiz debut. He guest starred as a fellow member of the swim team, which has been illegally doping with a compound infused with fish DNA that—oops!— is turning them into sea demons.

Shane West, Season 2, "Go Fish"

"Go Fish" was an early role as well for Shane West, who played another swimmer—he’s the one who reveals to Xander that the team is being doped via the steam room.

West would go on to star in Once and Again, ER and Salem.

Pedro Pascal, Season 4, "The Freshman"

He would become a fan favorite as the dashing bisexual warrior Oberyn Martell on Game of Thrones, but back in 1999, fledgling actor Pedro Pascal scored a role as a shy freshman at UC Sunnydale who thinks he might have a shot with Buffy. A few seconds later, he’s a vampire appetizer, and later in the episode he is dusted by Buffy.

After his skull-crushing departure from Thrones, Pascal moved on to Narcos, playing a DEA agent who takes down Pablo Escobar, and he’ll be back for season 3.

Kal Penn, Season 4, "Beer Bad"

The iconic stoner of the Harold and Kumar movies, Kal Penn played a beer-chugging college student who devolves into a Neanderthal thanks to some cursed brew in what is arguably one of the lamest Buffy episodes ever—and not just for Penn’s embarrassingly bad haircut.

Penn is also known for House and can currently be seen as a presidential speechwriter in ABC's Designated Survivor.

Amy Adams, Season 5, "Family"

The five-time Oscar nominee made her Buffy debut as Tara’s close-minded cousin Beth who believes, along with the rest of Tara’s family, that Tara's growing magical powers are actually demonic manifestations that she needs to suppress. (Hello homosexuality metaphor!)

Ironically, Adams' next role was in the straight-to-video Cruel Intentions prequel, playing the role originated by Sarah Michelle Gellar. She’s moved up in the world since then.

Amber Tamblyn, Season 6, "All the Way"

Janice is Dawn’s oft-mentioned but rarely seen BFF, and in her only appearance on the show sneaks out with Dawn for a double date with, as it happens in Sunndayle, two vampires. Janice gets bitten, but is rescued.

Amber Tamblyn, a General Hospital veteran, went on commune with God in Joan of Arcadia and later had stints on House and Two and a Half Men.

Ashanti, Season 7, "First Date"

Just the latest in a long line of Xander’s ill-fated romantic prospects, Lissa is a demon who attempts to sacrifice Xander over the seal to the Hellmouth (must be Tuesday!) before she is beheaded by Buffy.

Ashanti had already established herself as a potent R&B force when she appeared on Buffy. She later co-starred in the final season of Army Wives.

Rachel Bilson, Season 7, "Dirty Girls"

Rachel Bilson, who was soon to be immortalized as Summer Roberts in The O.C., played potential slayer Colleen, who is attacked by Lil’ Big Bad Caleb (Nathan Fillion, who went on to Firefly and Castle) as a message to Buffy. Colleen joins the other Potentials gearing up for battle with the First.

Dania Ramirez, Season 7, "Dirty Girls," Touched," End of Days"

Among the other Potentials is Dania Ramirez, who went on to score the role of A.J.’s girlfriend in The Sopranos and co-starred in Heroes and Devious Maids. Fun fact: Colleen and Caridad tag-teamed Xander in one of his erotic dreams.