Before they were besties, Mike and Sulley, your favorite monsters, were school-boy rivals.

Cue: The first time we met, we hated each other...

Yes, the two friends are back for "Monsters University" -- the prequel to the 2001 Pixar hit, "Monsters Inc." -- which sees the pair trying to out-scare each other on campus. Or, as the first full trailer for the film proclaims, "Before they were incorporated, they had to be educated." Of course, we all know how this love tale turns out, but who doesn't like an origin story?

Take a look at the full trailer for the prequel above. "Monsters University," starring John Goodman and Billy Crystal, hits theaters June 21.

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  • The Celebs

    The studio has lured some pretty good gets from celebrities either looking to impress their kids or earn a stable residual check, but Paul Newman is the cherry on top... or should that be the salad dressing?

  • 118. Annie Potts as Bo Peep ("Toy Story")

  • 117. John Turturro as Francesco Bernoulli ("Cars 2")

  • 116. Vanessa Redgrave as Mama Topolino/The Queen ("Cars 2")

  • 115. Tony Shalhoub as Luigi ("Cars 2")

  • 114. Cheech Marin as Ramone ("Cars")

  • 113. Whoopi Goldberg as Stretch ("Toy Story 3")

  • 112. Will Arnett as Horst ("Ratatouille")

  • 111. Roddy McDowall as Mr. Soil ("A Bug's Life")

  • 110. Wallace Shawn as Rex ("Toy Story")

  • 109. George Carlin as Fillmore ("Cars")

  • 108. Bruce Campbell as Rod "Torque" Redline ("Cars 2")

  • 107. Penn Jillette as TV Announcer ("Toy Story")

  • 106. Frank Oz as Jeff Fungus ("Monsters Inc.")

  • 105. Timothy Dalton as Mr. Pricklepants ("Toy Story 3")

  • 104. Craig Ferguson as Lord Macintosh ("Brave")

  • 103. Fred Willard as Shelby Forthright (live-action) ("WALL-E")

  • 102. Don Rickles as Mr. Potato Head ("Toy Story")

  • 101. Sigourney Weaver as the voice of the Axiom's computer ("WALL-E")

  • 100. R. Lee Ermey as Sarge ("Toy Story")

  • 99. Paul Newman as Doc Hudson ("Cars")

  • Pixar Employees

    Even amid the intense pressure to keep topping themselves movie after movie, some of the studio's best and brightest find time to voice a character or two, as did the late Joe Ranft who helped define modern animation.

  • 98. John Lasseter as John Lassetire ("Cars 2")

  • 97. Pete Docter as Kevin ("Up")

  • 96. Lou Romano as Snot Rod ("Cars")

  • 95. Lou Romano as Bernie Kropp ("The Incredibles")

  • 94. Andrew Stanton as Crush ("Finding Nemo")

  • 93. Andrew Stanton as Evil Emperor Zurg ("Toy Story 2")

  • 92. Brad Bird as Ambrister Minion ("Ratatouille")

  • 91. Brad Bird as Edna Mode ("The Incredibles")

  • 90. Joe Ranft as Red ("Cars")

  • 89. Joe Ranft as Jacques ("Finding Nemo")

  • 88. Joe Ranft as Lenny ("Toy Story")

  • John Ratzenberger

    The sardonic postal worker from "Cheers" has found a home in every single Pixar movie, and neither snow nor rain nor heat nor gloom of night stays him from doing so. His bad guy straight out of Jack Kirby-era "Fantastic Four" is the hilarious punchline of "Incredibles."

  • 87. John Ratzenberger as Tom ("Up")

  • 86. John Ratzenberger as Mustafa ("Ratatouille")

  • 85. John Ratzenberger as the school of Moonfish ("Finding Nemo")

  • 84. John Ratzenberger as Mack ("Cars 1 & 2")

  • 83. John Ratzenberger and Kathy Najimy as John and Mary ("WALL-E")

  • 82. John Ratzenberger as P.T. Flea ("A Bug's Life")

  • 81. John Ratzenberger as Hamm ("Toy Story 1,2, & 3")

  • 80. John Ratzenberger as The Abominable Snowman ("Monsters Inc.")

  • 79. John Ratzenberger as The Underminer ("The Incredibles")

  • The Loners

    "Lawrence of Arabia" himself lent an extra air of gravitas to the stuck-up food critic who gets magically transported back to his childhood via a simple peasant dish.

  • 78. Teddy Newton as Chatter Telephone ("Toy Story 3")

  • 77. Bud Luckey as Chuckles ("Toy Story 3")

  • 76. Willem Dafoe as Gill ("Finding Nemo")

  • 75. Denis Leary as Francis ("A Bug's Life")

  • 74. Jeff Garlin as Captain B. McCrea ("WALL-E")

  • 73. Peter O'Toole as Anton Ego ("Ratatouille")

  • The Bad Parents

    For years comedian Patton Oswalt used Brian Dennehy as a punchline in his act, so it was fitting that the great character actor should wind up playing his garbage eating, philistine rat of a father.