When we watch cartoons sometimes you hear a familiar voice but can’t quite put your finger on it. That’s because we’re so invested in the story line, we don’t even realize that the voice we’re hearing belongs to some of Hollywood’s most famous celebrities.

There are some that are pretty obvious, for example, we all know that Eddie Murphy voices Donkey in the movie “Shrek” and Ellen DeGeneres gives the quirky voice to Dory in “Finding Nemo.” However, not all of our favorite cartoon characters sound like the voice actor. Check out some of these lesser known voices to your favorite cartoon characters.

1. Fergie – Sally Brown in “The Peanuts” – We bet you wouldn’t have guessed this one in a million years. While we’ve watched Fergie sing for years now, even before we knew her as Fergie, we first heard the American pop icons voice when she starred as Sally Brown in “The Peanuts.”

2. Oprah Winfrey – Eudora in “The Princess and the Frog” – This talk show host isn’t a stranger to acting, but did you know that she played Eudora, Tiana’s mom, in “The Princess and the Frog?” Oprah’s name is now on the list of the first voice actors to be part of a Disney African-American princess movie.

3. Whoopi Goldberg – Shenzi in “The Lion King” – Whoopi has a very distinct voice, but if you were engrossed in the movie, you might not have realized that Shenzi’s voice belonged to the funny actress.

4. Vin Diesel – “The Iron Giant” – Before Vin Diesel became recognized as the face for “The Fast and the Furious”, he voiced the giant robot in “The Iron Giant.” He was a hit at producing the guttural sounds the giant made, which also likely helped him prepare for his future role as Groot in “Guardians of the Galaxy.”

5. Bruce Willis – Spike in “The Rugrats Movie” – The tough guy who starred in movies like “The Fifth Element” and “Die Hard” really was the voice behind the goofy dog in “The Rugrats Movie.” While Spike only barked on the television series, in the movie, Spike had a lot to say.

6. Rowan Atkison – Zazu in “The Lion King – Most of us don’t really know what the “Mr. Bean” star sounds like. But in “The Lion King” it is his pompous English voice that sets the perfect tone for Zazu.

7. Michael Cera – Brother Bear in “The Berenstain Bears” – The “Arrested Development” star was known as the voice behind the littlest cartoon bear before he became known as the awkward George Michael.

8. Meg Ryan – “Anastasia” – If you were to dye Meg Ryan’s hair red, she would pretty much turn into a real-life Anastasia. The “Sleepless in Seattle” star worked alongside John Cusack in “Anastasia” who was the voice actor for Dimitri.

9. Jay Leno – The Crimson Chin in the “Fairly Odd Parents” – It would only make perfect sense to have Leno play the voice of the Crimson Chin. The former late night host has a prominent chin himself, but unlike the Crimson Chin, he doesn’t have any special powers.

10. Mila Kunis – Meg Griffin in “Family Guy” – “That 70s Show” star Mila Kunis plays the emotional and self-conscious teenage girl on the television show “Family Guy”, although most of us probably never noticed.

11. Michael J. Fox – “Stuart Little” – Fox lent his voice to the spunky little cartoon mouse and most of us probably never noticed. How did we not notice the voice of the man who played Alex in “Family Ties?”

How many of these cartoon characters did you connect with the famous voice behind them? Share this story with your friends and see if they knew them all.