Even though Monsters University is only a few months away, Pixar has been keeping the voice cast under wraps.  Today, EW is reporting that Nathan Fillion, John Krasinski, and Bonnie Hunt will be voicing new monsters in the upcoming prequel.  Fillion and Krasinski are newcomers to the Pixar world, but Hunt has been a longtime collaborator with the studio having voiced characters in A Bug's Life, Cars, Toy Story 3, and Monsters, Inc. (although she'll be voicing a new character).

Hit the jump for descriptions of Fillion, Krasinski, and Hunt's characters, along with some new images.  The film also features the voices of Billy Crystal, John Goodman, Steve Buscemi, Helen Mirren, Dave Foley, Sean Hayes, Joel Murray, Peter Sohn, Aubrey Plaza, Tyler Labine, Bobby Moynihan, Julie Sweeney, Alfred Molina, Beth Behrs, and of course, John Ratzenberger.  Monsters University opens in 3D on June 21st.

Images via EW.

Fillion voices Johnny Worthington, a horned monster, and the "confident president of Roar Omega Roar (ROR), a Monsters University fraternity that prides itself on its notable Scarers."  Krasinski gives voice to "'Frightening' Frank McCay, a Scaring super star at Monsters, Inc."  Hunt will be lending her voice to Mike Wazowski’s grade school teacher Karen Graves.

It's a stacked voice cast, and I imagine that while there are a lot of actors attached, most will be minor roles.

Here's the full voice cast courtesy of Disney/Pixar:

The voice cast includes the following:

·         Billy Crystal (“Parental Guidance,” “When Harry Met Sally,” “City Slickers”) reprises his role as Mike Wazowski, now a college-age monster who follows his dream of becoming a Scarer at Monsters University.

·         John Goodman (“Argo,” “Flight,” “Trouble With the Curve”) returns as James P. Sullivan (Sulley), an overly confident, young hotshot Scaring student at Monsters University.

·         Steve Buscemi (“Boardwalk Empire”) rejoins the monster world as Randy Boggs, a Monsters University freshman who is ready to experience all that college has to offer (if only he can curb his habit of disappearing).

·         Helen Mirren (“Hitchcock,” “The Queen”) gives voice to Dean Hardscrabble, legendary Scarer and hard-to-please head of Monsters University’s prestigious School of Scaring.

·         Alfred Molina (TNT’s “Monday Mornings,” “The Da Vinci Code,” “Frida”) is the voice of Professor Knight, an esteemed professor in Monsters University’s School of Scaring.

·         Dave Foley (TV’s “NewsRadio,” “The Kids in the Hall”) as Terry Perry, the skeptical half of a bickering two-headed monster and dedicated Oozma Kappa (OK) brother.

·         Sean P. Hayes (“The Three Stooges,” TV’s “Up All Night”) gives voice to Terri Perry, the more sensitive side of a two-headed Oozma Kappa (OK) fraternity brother with Scaring aspirations.

·         Joel Murray (TV’s “Mad Men,” “Two and a Half Men”) voices Don Carlton, a “mature” student at Monsters University and a founding member of the Oozma Kappa (OK) fraternity.

·         Pixar’s Peter Sohn (“Ratatouille,” “Small Fry”) provides the voice of Scott “Squishy” Squibbles, an undeclared sophomore at Monsters University and Oozma Kappa (OK) fraternity member who still lives with his doting mother.

·         Charlie Day (“Horrible Bosses,” “Pacific Rim,” TV’s “It’s Always Sunny in Philadelphia”) provides the voice of the incomparable Art, an Oozma Kappa (OK) fraternity brother with a questionable past.

·         Nathan Fillion (“Much Ado About Nothing,” “Percy Jackson: Sea of Monsters,” TV’s “Castle”) portrays Johnny Worthington, the confident president of Roar Omega Roar (ROR), a Monsters University fraternity that prides itself on its notable Scarers.

·         Bobby Moynihan (NBC’s “Saturday Night Live,” HBO’s “Girls,” DreamWorks Studios’ “Delivery Man”) helps bring to life Chet Alexander, a yes-monster member of the Roar Omega Roar (ROR) fraternity.

·         Julia Sweeney (TV’s “The Goode Family,” “Saturday Night Live”) lends her voice to Ms. Squibbles, indulgent mother to Monsters University sophomore Scott “Squishy” Squibbles.

·         Aubrey Plaza (“To Do List,” TV’s “Parks and Recreation”) gives voice to Claire Wheeler, the somber president of Monsters University’s Greek Council and emcee for the annual Scare Games.

·         Tyler Labine (“Tucker & Dale vs. Evil,” “Mad Love”) was tapped to voice Brock Pearson, vice president of the Greek Council and enthusiastic emcee of the Scare Games.

·         John Krasinski (“Promised Land,” TV’s “The Office”) provides the voice of “Frightening” Frank McCay, a Scaring super star at Monsters, Inc.

·         Bonnie Hunt (TV’s “The Bonnie Hunt Show,” “Cheaper By the Dozen”) was called on to provide the voice of young Mike Wazowski’s grade school teacher Karen Graves.

·         Beth Behrs (TV’s “2 Broke Girls”) serves as the voice of Carrie Williams, fearless leader of the Python Nu Kappa (PNK) sorority.

·         John Ratzenberger (“Cheers,” Disney•Pixar’s feature films) returns to the Pixar recording studio as the voice of a Monsters, Inc. employee.

Here are some images of the monsters attending MU:

Here’s the official synopsis for Monsters University:

Mike Wazowski and James P. Sullivan are an inseparable pair, but that wasn’t always the case. From the moment these two mismatched monsters met they couldn’t stand each other. Monsters University unlocks the door to how Mike and Sulley overcame their differences and became the best of friends.