Fans of Buffy the Vampire Slayer and Angel already know what we're about to tell you: every famous actor you can think of off the top of your head has probably been on one of those two shows at some point in time. Future Academy Award winners and nominees, award-winning screenwriters, and video game impresarios have all graced the small screen as a part of the world of Sunnydale (and Angel's version of Los Angeles), and with Joss Whedon directing or co-directing blockbusters like the first two Avengers movies and Justice League, many of the actors that put in work on his old shows are finding themselves with star turns in superhero movies.

Buffy and Angel were shows that must have been a dream for actors -- they were either asked to be as emotionally bare as they could, or they got to put on incredible demon makeup for a few weeks and crack wise; if they were extra lucky, they got to do both. With the recent passing of Buffy the Vampire Slayer's 20th anniversary in 2017 (man, doesn't that just make you feel ancient?), we took a look back at some of the coolest cameos and early roles for stars in the Buffyverse. Here's 18 of our favorites!

18 AMBER TAMBLYN

The daughter of Russ Tamblyn, who starred in West Side Story as Riff and appeared as Dr. Jacoby in Twin Peaks, Tamblyn is no stranger to the acting game. She became a star in her own right in the mid-'00s primetime series, Joan of Arcadia; she later appeared in The Sisterhood of the Traveling Pants, The Ring, and 127 Hours. Near the end of her tenure on General Hospital, Tamblyn appeared in the Buffy the Vampire Slayer episode, "All the Way," as a high school friend of Dawn's.

While Halloween is usually a calm night for demons and such, Dawn pairs up with Tamblyn's Janice and two boys to prank an old man; the situation escalates when the boys are revealed to be vampires, thieves and killers. Tamblyn recently co-wrote and directed the film Paint It Black.

17 KAL PENN

Kal Penn has several claims to fame: the infamous Harold and Kumar movie series, a supporting role for several years on House, an acclaimed appearance in the adaptation of Jhumpa Lahiri's The Namesake, and working for President Obama. Penn also has the distinction of having appeared in two separate Buffyverse shows at different times.

First, he appeared on Buffy as Hunt, a collegiate drinking buddy of Buffy's who partakes in cursed beer that causes the drinker to turn into a literal neanderthal; two years later, he appeared on Angel as a mystic working with the mysterious partners of Wolfram and Hart, hired to attack Cordelia. Penn has since returned to acting from politics, with several movies in the last two years and a gig as a series regular alongside Kiefer Sutherland on Designated Survivor.

16 JEFFREY DEAN MORGAN

A familiar face to faithful CBR readers like you, Jeffrey Dean Morgan has been acting since 1981; he really hit his stride in 2005, appearing in a succession of three hit shows (Weeds, Supernatural, and Grey's Anatomy). However, his turn as Azazel in Supernatural was not his first brush with the supernatural -- three years earlier, he appeared on Angel.

In the third season episode, "Provider," Angel Investigations takes a case from a man who wants to destroy a vampire nest; the man, played by Morgan, was eventually revealed to be masquerading as his former boss, who wanted to destroy the vampire nest and avenge his friend's murder. Since then, Morgan has gone on to starring roles in Magic City and, obviously, The Walking Dead, where he plays seasons seven and eight antagonist, Negan.

15 SEAN GUNN

You might recognize him as everyone's favorite Ravager, Kraglin, but Sean Gunn has been around for a long time. The brother of Guardians of the Galaxy writer and director, James Gunn, Sean comes from a very artistic family. Though he first came to prominence as Kirk Gleason, one of the resident oddballs of Stars Hollow on Gilmore Girls, he appeared twice on Angel.

Oddly, in his two appearances, he played two separate characters, and the episodes were only four weeks apart -- the kind of thing continuity fans would not stand for these days. He appears as a peaceful demon who plays Jiminy Cricket to half-human/half-demon layabout Doyle in the ninth episode of the first season, and then in the 13th, he plays the proprietor of a health spa who is hiding a group of female demon refugees.

14 WENTWORTH MILLER

Most familiar nowadays as Leonard Snart (aka Captain Cold) on The Flash and Legends of Tomorrow, Wentworth Miller's first big break came in 2005 as the star of FOX's Prison Break. Miller is also a successful screenwriter, with several nominations under his belt for penning Park Chan-Wook's English-language debut, Stoker. Miller's very first role, however, came seven years before Prison Break, in the second season of Buffy the Vampire Slayer, playing swim-team-superstar-turned-fish-person, Gage Petrozi.

While Xander is undercover as a nobody member of the swim team, Gage is the alpha fish, leading the rest of the team on their murderous rampages and chewing the heck out of the scenery. After struggling with suicidal depression that came to a head in 2010, Miller's acting slate has been light aside from his Arrowverse appearances; he mostly focuses on screenwriting now.

13 JEREMY RENNER

It's impossible to go to a movie theater these days and not see a poster or an ad for a new Jeremy Renner movie. After starting out with acclaimed roles in independent films, such as The Heart is Deceitful Above All Things and the title role in 2002's Dahmer, Renner's portrayal of a haunted bomb disposal specialist in 2008's The Hurt Locker turned him into the action star he is today, with credits under his belt for Mission: Impossible, The Avengers, and The Bourne Legacy.

In 2000, Renner appeared in a first season episode of Angel entitled "Somnabulist;" in the episode, Angel fears he is killing while he's asleep and not in control of his actions, before realizing that his former protege (played by Renner) is the one committing the crimes, using Angel's former MO.

12 STEPHEN TOBOLOWSKY

One of those classical "those guys," a seemingly ubiquitous character actor who brings an amusing professorial air to many of his characters, Stephen Tobolowsky has almost certainly graced your television screen at some point in the last week. When Joss Whedon began preparing a pilot for what became the television version of Buffy the Vampire Slayer, he directed his own pilot featuring actors who didn't make it into the network premiere; Tobolowsky was one of the fallen. He originally appeared as Principal Flutie, a (short-lived) role that was eventually played by Ken Lerner.

Since then, Tobolowsky has been steadily working in film and TV, as well as writing and directing plays; he also starred in the documentary Stephen Tobolowsky's Birthday Party (it's exactly what it sounds like), and he currently hosts a podcast for /Film called The Tobolowsky Files.

11 JOHN HAWKES

Academy Award nominee John Hawkes started his career as a stalwart character actor, appearing in big budget action movies like Congo and genre pieces like From Dusk till Dawn. He settled into a groove of solid roles, playing Danny McBride's straight-laced brother in four seasons of Eastbound & Down, and merchant Sol Star on two seasons of Deadwood, before shooting to prominence with his Academy Award-worthy performance in Winter's Bone. 

Twelve years before that, Hawkes appeared in Buffy the Vampire Slayer, in the second season episode "I Only Have Eyes for You." In the episode, people at Sunnydale High are being possessed by the ghosts of a student and a teacher he was having an affair with in 1955; the student shoots the teacher at the end of an argument, and the argument is replayed by many characters, including Hawkes as the school janitor.

10 MICHAEL HARNEY

Michael Harney is most recognizable today as the hangdog Corrections Officer, Sam Healy, in charge of the women's prison at Litchfield Penitentiary in Netflix' Orange is the New Black. Harney has also made guest appearances for a handful of episodes on shows like Deadwood, Weeds, and True Detective, alongside his long and storied career on stage. Harney appeared on Buffy the Vampire Slayer in one of its weirdest and most striking episodes, "Restless."

By the second-to-last episode of the fourth season of the show, all the major plotlines had been tied up, leading Joss Whedon to write and direct "Restless" as an epilogue to the season, as well as a look forward, with surreal filming and editing while each main character dreamt about their past and future. Harney appears in Xander's dream as a manifestation of The First Slayer before tearing out Xander's heart.

9 ROBIN ATKIN DOWNES

Robin Atkin Downes is one of the busiest men in show business, with almost 400 acting credits to his name in the last 20 years. You may not recognize him, and that's fine -- Downes is a master of motion capture, voice over, and other under-credited but essential roles in film and video games. He has appeared in several of the Uncharted games, the Metal Gear Solid franchise, and most recently as the Riddler in Batman: The Enemy Within from Telltale Games.

Downes' first on-screen appearance was a second season episode of Buffy in which he plays Machida, the eldritch reptile god to whom a fraternity was sacrificing pretty young women (almost including Buffy and Cordelia). He also appeared as a Pockla Demon in the second season of Angel several years later.

8 ZACHERY TY BRYAN

Zachery Ty Bryan is most familiar as Brad, the older of the two Taylor children on Home Improvement, though he has continued to make sporadic appearances in films and television shows. Among his roles after Home Improvement ended in 1999 is Peter Nichols, from "Help," the 14th episode of Buffy the Vampire Slayer's seventh and final season.

Peter is a member of group of boys who try to sacrifice a friend of Dawn's to a demon for infinite riches; their plan is foiled, and while the demon does show up, he gets fried and then bites Peter. Fun fact: the episode also featured the first use of "Google" as a verb, so enjoy feeling old with that knowledge. Bryan hasn't acted in anything since 2009, but he has embarked on a robust producing career.

7 JOHN RITTER

John Ritter as Ted on Buffy

John Ritter is no stranger to the American television-viewer -- he starred for several years as Jack Tripper, the supposedly-gay male roommate living with two women in Three's Company (and, forgettably, Three's a Crowd). He appears in the 11th episode of the second season of Buffy the Vampire Slayer, "Ted," as the eponymous Ted.

A new man who begins dating Joyce Summers, Buffy and the gang are suspicious of him, though everyone attributes that to Buffy distrusting a new man in her mother's life -- little did everyone know that Ritter's character would turn out to be a robot, built by a man named Ted, before the robot stole Ted's wife and kept her in a bunker. He continued to try and gather women who looked like Ted's wife for 50 years. Ritter himself tragically passed in 2003 while working on 8 Simple Rules for Dating My Teenage Daughter.

6 EION BAILEY

Eion Bailey is most familiar as a television character actor, known for his recurring roles on Covert AffairsRay Donovan, and Stalker; Bailey also appeared as August (aka Pinocchio) on Once Upon a Time, and starred as Private Webster in the HBO miniseries, Band of Brothers. But Bailey's first role came in 1997, in the Buffy the Vampire Slayer episode, "The Pack."

In the episode, the sixth of the first season, Xander is possessed by an animal spirit, as are several of his classmates -- their behavior gets more and more aggressive, leading them to bound down the hallways on fours like dogs and to literally eat the principal. Bailey co-stars as one of the predatory high schoolers who torments another student, leading Xander to follow them and accidentally become possessed himself.

5 DAVID DENMAN

This one is an easy one to miss: known to the world at large as Roy, Pam's erstwhile fiancee on the American version of The Office, David Denman appeared in several episodes of Angel as Skip, a supremely friendly and pop-culture savvy demon that the Angel Investigations team occasionally turn to for information and advice about the Powers That Be.

While the easy going demeanor of Skip remained a constant, he eventually became a threat to the team, a threat not lessened by the sheer power he possessed; Skip was a demon of unknown species, but he was heavily armor-plated in a visually striking, asymmetrical fashion, and he possessed retractable wrist blades. Joss Whedon stated in the lead up to the Buffy the Vampire Slayer: Season Eight comics that Skip was one of his favorite demon designs -- who knows why Pam didn't stay with him in the end.

4 RIKI LINDHOME

Born Erika Lindhome, Riki is most recognizable as one half of Garfunkel and Oates, alongside fellow character actress Kate Micucci, and the host of Making It, a podcast from the Nerdist network; she also currently stars in and created Another Period with Natasha Leggero. But in 2002, she landed one of her first roles out of college as a featured player in "Him," a seventh season episode of Buffy the Vampire Slayer.

In the episode, a high school football player has an enchanted letterman's jacket that makes all women fall in love with him -- leading Dawn to fall for him and try out for cheerleading. Lindhome plays Cheryl, another cheerleading hopeful who tosses out the idea that they all use chairs in their routines, like the Lakers girls.

3 SHANE WEST

Before his star turn in A Walk To Remember opposite Mandy Moore, Shane West thought he was going to be a musician. Growing up in a musical family, West grew up imagining himself in a band, and found himself at the age of 15 in Los Angeles, trying to become an actor. In 1997, while he was still working smaller appearances on television shows, he appeared in "Go Fish," an episode in the second season of Buffy the Vampire Slayer.

The Slayer gang investigates the fact that the entire Sunnydale High swim team seems to be turning into giant gill monsters -- while Xander goes undercover as a swimmer to try and find out who's making gill monsters and how they're doing it, the gang try to keep the gill monsters from killing again. West plays Sean, a swimmer who goes "skinless dipping" before being turned into a gill monster.

2 KEN MARINO

Ken Marino is most well-known for playing lovable goofballs, from The State to Party Down to Brooklyn Nine-Nine, as well as his collaborations with David Wain -- Marino has starred in many Wain productions, like Wet Hot American Summer and Role Models, while also co-writing several of them.

In the first season of Angel, Marino plays a famous photographer who goes on a date with Cordelia that ends with her very much in a family way; over the course of the episode, the Angel gang believes that he is a demon, before discovering that he is only a human that a demon is using as a host -- regular human men have sex with women and impregnate them with demon babies, and in exchange, the demon grants fame and power to the men. If it hadn't been so early in his career, it would be a great example of playing against type.

1 AMY ADAMS

Before she got to become a live-action Disney Princess, and before she took the role of Lois Lane, Amy Adams was putting in work. One of the most consistent actresses in Hollywood, Adams has had a career that is nearing the end of its second decade, littered with Academy Award nominations. While she was putting in work in the early '00s, in hits like Psycho Beach Party and the direct-to-video Cruel Intentions 2, she made several appearances in popular shows.

In the fifth season of Buffy the Vampire Slayer, as the gang of usual suspects was preparing to battle Glory, the god of a hell dimension with her sights set on Sunnydale, Tara wrestles with her own demons: her family. Adams plays Tara's fundamentalist, anti-magic cousin, who tries to get her to give up her magic for good.