Marvel's 'Guardians of the Galaxy' hits theaters this Friday, and it's packed with familiar faces (and voices), like Chris Pratt, Bradley Cooper, Vin Diesel, and new favorite Karen Gillan. And while they're superhero superstars now, that wasn't always the case -- it may be hard to believe now, but there was a time when you didn't know their names. Join us as we take a look back at the cast of 'Guardians of the Galaxy' to see what they were up to before they were famous.

Chris Pratt, Peter Quill/Star-Lord

Marvel/Warner Bros.

Now: Chris Pratt, whom you know best as lovable goofball Andy on 'Parks and Recreation,' plays Peter Quill, aka Star-Lord, the leader of the 'Guardians of the Galaxy.' Abducted as a child and raised by aliens, Quill grows up to be an intergalactic outlaw before uniting with an unlikely group of heroes to save the universe.

Then: Pratt was discovered by actor-director Rae Dawn Chong while waiting tables at a Bubba Gump Shrimp Company restaurant and cast in the horror film 'Cursed 3,' but he got his big break as a supporting star on the WB series 'Everwood' (above right). He also had a recurring guest role on 'The O.C.' and appeared in the 'Strangers with Candy' movie.

Zoe Saldana, Gamora

Marvel/Columbia Pictures

Now: Zoe Saldana plays Gamora, a green-skinned alien badass who, along with her adopted sister Nebula, was raised by Thanos. But she doesn't like what the big guy is up to, so she joins the Guardians to set things right. Saldana has established herself as a sci-fi fixture in recent years, with roles in the 'Star Trek' and 'Avatar' films.

Then: Saldana's first role was as a dancer in the 2000 ballet drama 'Center Stage.' She also appeared in teen films like 'Get Over It,' 'Crossroads' (with Britney Spears!), and 'Drumline' before landing the breakout role of Anamaria in 'Pirates of the Caribbean: The Curse of the Black Pearl.'

Dave Bautista, Drax The Destroyer


Now: Dave Bautista plays Drax, an alien warrior whose quest for revenge against Ronan the Accuser inspires him to join up with the Guardians. And just because he comes from the world of WWE professional wrestling (where he's known as Batista), that doesn't mean he's the weakest link in the film -- he's actually the funniest character.

Then: Dave Bautista made his wrestling debut in Ohio Valley Wrestling in 2000 under the name Leviathan before joining the WWE in 2002, where he made his debut as Deacon Batista, a villainous character on the show. He won several championship titles before leaving the WWE in 2010. He's also appeared in films like Werner Herzog's 'My Son, My Son, What Have Ye Done?,' 'The Man with the Iron Fists' and 'Riddick.'

Vin Diesel, Groot


Now: Vin Diesel, star of the 'Fast and Furious' and 'Riddick' franchises, lends his booming voice to the character of Groot, a tree-like humanoid who acts as muscle for his companion, Rocket Raccoon. Don't let his imposing size fool you: he's pretty adorable.

Then: After shooting amateur breakdancing videos on VHS in the 80s (above), Diesel got his official start in the 1997 film 'Strays', which he wrote, produced, directed, and starred in. It was just a year later that he caught his big break with a supporting role in Steven Spielberg's 'Saving Private Ryan,' followed by the memorable role as the voice of the Iron Giant in 'The Iron Giant.'

Bradley Cooper, Rocket Raccoon

Marvel/USA Films

Now: Bradley Cooper voices Rocket Raccoon, a genetically engineered raccoon who just so happens to also be a bounty hunter and a pretty awesome weapons specialist. Cooper was also recently nominated for Academy Awards for his performances in the David O. Russell films 'American Hustle' and 'Silver Linings Playbook.'

Then: Cooper's first role was in the David Wain summer camp cult comedy classic 'Wet Hot American Summer,' in which he played Ben, a gay camp counselor trying to organize a musical with Amy Poehler's character. He went on to appear in the films 'My Little Eye' and 'Bending All the Rules' before he gained attention for playing Rachel McAdams' jerky fiancé in 2005's 'Wedding Crashers.'

Lee Pace, Ronan


Now: Lee Pace stars as Ronan, a radical member of the Kree race who holds a grudge against the Xandarians. Ronan asks Thanos to wipe out the planet of Xandar in exchange for his help in retrieving a powerful artifact. You also know Pace from his role in the 'Hobbit' film as Thranduil, and from the new AMC series 'Halt and Catch Fire.'

Then: Pace made his film debut in 2003's 'Soldier's Girl' (above right), in which he played a very beautiful transgender woman. He also appeared in a 2002 episode of 'Law and Order: SVU.' But it wasn't until his roles in the shows 'Wonderfalls' and 'Pushing Daisies,' as well as the 2006 film 'The Fall,' that audiences sat up and began to take notice of his talent.

Michael Rooker, Yondu

Marvel/Greycat Films

Now: Michael Rooker plays Yondu, a blue-skinned alien bandit and the leader of the Ravagers; he's also the closest thing to a father figure that Peter Quill has. This isn't Rooker's first time working with director James Gunn -- he also appeared in his previous films, 'Slither' and 'Super.' And you probably recognize him from his role on 'The Walking Dead.'

Then: Rooker made his debut in the acclaimed 1986 film 'Henry: Portrait of a Serial Killer.' He also starred in movies like 'Above the Law,' 'Days of Thunder' (which also featured his future 'Guardians' co-star John C. Reilly), and 'JFK,' and gave a memorable turn in Kevin Smith's 'Mallrats.'

Karen Gillan, Nebula


Now: Karen Gillan plays the blue-skinned and deadly Nebula, who -- along with Gamora -- was adopted and genetically modified by Thanos to serve as a weapon. You may have also recently seen Gillan in the horror film 'Oculus.'

Then: Gillan got her start on the Scottish series 'Rebus' and the British series 'The Kevin Bishop Show' before landing a guest spot on a 2008 episode of 'Doctor Who' titled "The Fires of Pompeii." She definitely left an impression because in 2010, she joined the series as the Doctor's new companion, Amy Pond, and remained on the show until 2013.

Djimon Hounsou, Korath


Now: Djimon Hounsou plays Korath, a Kree ally and talented hunter who helps Ronan track down and attempt to stop the Guardians. Hounsou also recently lent his voice to 'How to Train Your Dragon 2' and will appear in 'Fast and Furious 7,' reuniting him with his 'Guardians' co-star Vin Diesel.

Then: Hounsou, a Beninese actor, made his acting debut on a 1990 episode of 'Beverly Hills 90210' as a bouncer. He also had bit roles in 'Unlawful Entry' (for which he was nominated for an award for "most successful Beninese role") and 'Stargate' before landing a part in Steven Spielberg's 'Amistad.'

John C. Reilly, Rhomann Dey


Now: John C. Reilly stars as Rhomann Dey, a corpsman in the Nova Corps, the military force on the planet of Xandar. One of our most versatile actors, he has recently appeared in 'Anchorman 2: The Legend Continues,' reprised the role of Dr. Steve Brule on a new season of the Adult Swim series 'Check It Out!,' and narrated the Disney documentary 'Bears.' He appears next in the indie comedy 'Life After Beth.'

Then: Reilly got his start in 1989 appearing with Sean Penn in the films 'Casualties of War' and 'We're No Angels' before landing supporting roles in 'Days of Thunder' and 'Hoffa.' He went on to star in movies like 'What's Eating Gilbert Grape?' (above right) and 'The River Wild' before starring in Paul Thomas Anderson's debut film 'Hard Eight,' which led to Reilly starring in Anderson's films 'Boogie Nights' and 'Magnolia.'

Benicio del Toro, Taneleer Tivan/The Collector


Now: Benicio del Toro plays Taneleer Tivan, aka The Collector, an eccentric and obsessive resident of the planet Knowhere, who keeps a collection of intergalactic plants, animals, relics, and species. He's after the same artifact that Thanos wants, of course. Del Toro recently appeared in 'Savages,' and can be seen next in Paul Thomas Anderson's 'Inherent Vice.'

Then: Del Toro made his acting debut as Duke, the Dog-Faced Boy in the Pee-wee Herman film 'Big Top Pee-wee.' He also appeared in 'License to Kill,' 'Fearless,' and 'China Moon' before landing his breakout role as Fred Fenster in 'The Usual Suspects.'

Josh Brolin, Thanos

Marvel/Warner Bros.

Now: Josh Brolin does the motion capture thing as the villainous, power-hungry Thanos, who will stop at nothing to collect all the Infinity Stones, which will enable him to become the most powerful being in the universe. Brolin also recently appeared in 'Oldboy,' stars next in 'Sin City: A Dame to Kill For,' and reunites with Benicio del Toro for 'Inherent Vice.' He'll also (presumably) reprise the role of Thanos for 'Avengers: Age of Ultron.'

Then: Brolin first graced the silver screen as Brandon Walsh, the big brother in the cult classic kids' film 'The Goonies.' He went on to star in movies like 'Thrashin',' 'Bed of Roses,' and 'Mimic' before gaining a little more attention with roles in films like 'The Mod Squad' and 'Hollow Man.'