After Summit Entertainment announced eight new supporting [article id="1650979"]castmembers for "Breaking Dawn,"[/article] fans reacted with a collective, "Um, who?"

Yes, folks like Olga Fonda and Masami Kosaka don't exactly have the name recognition of a Kristen Stewart or a Taylor Lautner, but each new castmember comes to the Twi-verse with previous acting credits and some online video. We gathered a handy guide for Twi-hards.

Olga Fonda

This Russian model and actress has quietly been building her Hollywood résumé in recent years, with brief appearances in shows like "How I Met Your Mother" and "Entourage." This past summer she was cast in Hugh Jackman's upcoming futuristic boxing drama, "Real Steel."

"Living in Los Angeles has given me an opportunity to pursue my dreams and has been able to open the doors to unlimited possibilities," Fonda told Maine's Kennebec Journal last year.

A 2007 YouTube video showcases Fonda at Los Angeles Fashion Week: her easy smile, her accented English and her sultry moves on the runway.

"So many girls trying to be models, like, 'Oh my god, I want to be a model!' Nobody really knows the reality of it," she said. "It's a lot of hard work, but at the same time it's a lot of fun."

Amadou Ly

Born in Senegal, Ly and his personal story became well-known in 2006 when a New York Times article reported how he had been abandoned by his mother and could not board a plane to Atlanta after his East Harlem robotics team won a spot in a national competition. The exposure attracted the attention of politicians and Hollywood, and he now has a foreign student visa. He's also building his acting résumé with theater work, a small role in "Law & Order" and several short films.

Masami Kosaka

Kosaka has already shared screen time with two "Twilight" stars, thanks to one scene in "The Runaways" in which he played a Japanese journalist interviewing Stewart and Dakota Fanning's characters. The actor has uploaded his reel to YouTube, showing off not only that "Runaways" scene, but his work in "FlashForward," "What About Brian" and a low-budget action flick called "The Legend of Samurai."

Wendell Pierce

Pierce has been part of the HBO family since 2002, first starring in "The Wire" and currently in "Treme," set in New Orleans where he also lives and which he never sees accurately portrayed in movies or TV.

"Hollywood hasn't been helpful with that; if I see another movie where everyone has Cajun accents and some guy in a jester hat is dancing behind a window, I'll go crazy," he told MTV News earlier this year. "People come here and ... then they're pleasantly surprised to see how Mardi Gras is a family affair. ... [It's] not just 'Girls Gone Wild.' It's also the biggest block party in the world, where people get to meet their neighbors and celebrate with their neighbors ... on an annual basis."

Sebastiao Lemos

The floppy-haired, goateed Brazilian native has appeared in the TV series "Força-Tarefa," which literally translates to "Task Force," and a 2008 Portuguese-language short film titled "Cara e Coroa," which can be found on YouTube.

According to a Brazilian "Twilight" fan site, in the short, Lemos plays a cop with ties to organized crime.

Janelle Froehlich

Froehlich appeared in the short-lived, syndicated, bilingual drama series "Hacienda Heights," which aired on a local Los Angeles TV channel. This summer she uploaded an audition video to YouTube for an unspecified project in which she appears to play a young journalist.

Ty Olsson

Olsson has been working steadily on the big and small screen for more than a decade, and as you might expect, his mug is all over YouTube: from interview segments on local news channels to spots on TV shows like "Men in Trees." He played a real-life 9/11 victim in "Flight 93" and was last seen on the big screen in "2012."

What do you think of all these new castmembers? Who is your early favorite? Let us know in the comments!

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