In 2009, Dreamworks released Monsters vs Aliens, a 3-D animated film that dealt with the repercussions of two diametric species battling for dominance. The film follows the journey of Susan Murphy, played by Reese Witherspoon, following her transformation into a giant after being hit by a superpowered meteorite. Once the government learns of her otherworldly growth, she is taken to a secret facility, where she meets a colorful cast of monsters that have also been placed under federal holding.

RELATED: 10 Movies You Didn't Realize Were Made By DreamWorks

At the box office, the film did was a moderate success, which spawned a fresh franchise for the company. A short film, various television specials, as well as a show on Nickelodeon were produced, creating a fan base larger than that of the singular cinematic outing. Looking back on the supernatural adventure that started it all, here are ten things everyone missed about the main characters in Monsters vs Aliens. 

Hugh Laurie's Accidental Audition

Hugh Laurie as Gregory House in House MD

House star Hugh Laurie plays the pint-sized Dr. Cockroach in Monsters vs Aliens and his performance received critical acclaim. Abandoning the American accent he previously deployed, Laurie brings Dr. Cockroach to life with a drawling, high-toned English accent, pitch-perfect for the diminutive mad scientist.

Laurie was nominated for an Annie Award for his vocal work on the film, but what fans may not know is that earned his role in Monsters vs Aliens after producers saw a video of him accepting another award for his work on House, recognizing instantly that he was ideal for the part. 

Movie Monster Inspirations

The Gillman rising out of the water in Creature From The Black Lagoon

In a feature that is crafted as a love letter to classic monster movies it's only fitting that the production team of Monsters vs Aliens took inspiration from film history. Each of the main monsters in the film is a direct reference to a classic film in the genre, and while some connections are obvious, such as B.O.B. and The Blob, others may have been missed by audiences.

Susan is inspired by Attack of the 50 Foot Woman, The Missing Link is a reference to The Creature from the Black Lagoon, Dr. Cockroach is a play on The Fly, and Insectosaurus was inspired by the kaijū classic, Mothra. 

Office Connections

Without seeing their faces onscreen, it can be easy to overlook when recognizable stars lend their voices to animated productions. The Office, while highly-viewed at the time of the films release, had yet to reach the pinnacle of popularity that it has achieved in the age of streaming.

RELATED: The Office: 5 Reasons Toby Is The Scranton Strangler (& 5 Reasons It's Creed)

Subsequently, fans may have overlooked that four cast members in Monsters vs Aliens also appeared on The Office. Rainn Wilson plays the titular alien, GallaxharWill Arnett lends his voice to The Missing Link, and John Krasinski and Ed Helms round out the cast as Cuthbert and a news reporter, respectively.

The Stylings Of Susan

Ginormica standing in front of alien ships in Monstes vs Aliens.

The "monster" genre of cinema enjoyed its heyday during the mid-twentieth century and Monsters vs Aliens paid tribute to these classic titles throughout the film. Not only were the monsters themselves inspired by those that had come before, but the design of the protagonist, Susan, is a throwback in itself.

The production team wanted Susan to reflect this bygone era of Hollywood, and as such, her character was inspired by starlets from the time, most prominently, Bette Davis.

B.O.B. And His Abundance Of Bubbles

Monsters Vs. Aliens

B.O.B., voiced by Seth Rogen, was the breakout star of the movie. Audiences became enamored with the boisterous blue blob, eventually leading to him getting his own spin-off short film, B.O.B.'s Big Break.

RELATED: 10 Movie Franchise Spinoffs That Would Be Terrible (But We Want To See Anyway)

Adored as he is, even the most loyal fans of the franchise may not know that, according to producers, B.O.B. has over 12,000 bubbles inside of him that comprise his squishy shape.

Monstrous Transportation

Samsung 3D TV Monsters vs Aliens

When it came time for the monsters of the film to arrive in San Francisco, the government agency utilized a large transport ship to get them to the sunshine state. Fans of the movie may not be aware, however, that the vehicle used by the main characters was based off a real-life spacecraft.

The "Guppy," was one of the original aircraft designs that NASA created in order to transport spacecraft parts, a fitting tribute, as it falls in line with the mid-century throwbacks that populate the film.

Susan (Doesn't) Pack A Punch

monsters vs aliens mutant pumpkins from outer space short movie

During the climax of the film the monsters finally do battle with the invading aliens, fulfilling the promise made in the movies title. While the battle set piece is epic in scale and damage is undertaken by both factions, one of the main characters refrains from getting too physical.

One a repeat watch, viewers might notice that Susan herself never throws a punch at her enemies throughout the fight scene. Various inanimate objects are casualties of Susan's newfound strength, but the gigantic protagonist never uses her power directly against other living beings.

Flying Purple People Eater

In 1958, artist Sheh Wooley recorded the perennial hit, "The Purple People Eater." Lyrics in the song describe this unknown monstrosity "coming out of the sky" to eat purple people, but instead, joins a "rock n roll band."

RELATED: The 10 Best Dreamworks Villains, Ranked

Monsters vs Aliens is full of references to the time period in which this song was released, including a direct reference to the tune itself. The robotic probe that Gallaxhar sends from the sky is horned, purple and has one eye, a fitting touch for a classic song that remains a monstrous hit.

Madagascar Fan

The cast of Madagascar

Madagascar, another series produced by Dreamworks animation, remains one of the studios most lucrative franchises. Eagle-eyed fans may notice that in Monsters vs Aliens, the popularity of the four animal escapees extends beyond the borders of Earth itself.

When Gallaxhar addresses the world and announces his invasion plan, one of the many screens he utilizes is broadcasting the first Madagascar movie, proving that even invading aliens can take solace in tales of interspecies friendship.

Colbert Coincidence

Stephen Colbert, best known for his comedic takes on political issues, plays President Hathaway in Monsters vs Aliens. The casting choice is spot-on, as Colbert's connection to politics makes him an ideal choice to portray a fictional politician.

Ironically, the President bears a strong resemblance to Colbert, even though the character design was finalized before casting even began. The mid-credit reference to Hathaway "freezing his head" is also a link to Colbert, as he lists a step-by-step guide to cranial cryogenics in his book, "I Am America and So Can You."

NEXT: 10 Plot Holes In The Shrek Franchise