In 1993, professional basketball player Michael Jordan announces his retirement from the NBA to follow in his father's footsteps and turns to a career in baseball. Meanwhile the Nerdlucks, a group of criminal aliens led by their boss Mister Swackhammer (voiced by Danny DeVito), plot to capture the Looney Tunes, who really exist in a secret animated world called Looney Tune Land (hidden at the center of the Earth), and make them their newest attractions at Moron Mountain, a failing amusement park. Swackhammer believes enslaving the Tunes in this way will bring in more customers and save Moron Mountain from foreclosure.They arrive in Tune Land, and since the aliens aren't very intelligent or tall, the Tunes bargain for their freedom by challenging the Nerdlucks to a basketball game. To ensure their victory, the Nerdlucks return to Earth and steal the talent of Patrick Ewing, Larry Johnson, Charles Barkley, Muggsy Bogues, and Shawn Bradley, who are rendered incapable of playing basketball as a result. The Nerdlucks use the stolen talent to transform into gigantic creatures—now called the Monstars—that the Looney Tunes are unable to defeat.To help them win, the Tunes choose, abduct and recruit Michael, and he reluctantly agrees after the Monstars squash him into the shape of a basketball and bounce him around like one. A new arrival named Lola Bunny is added to the team thanks to her talent. Daffy Duck and Bugs Bunny go to Michael's house to collect what he needs to play, barely dodging his family dog Charles. Michael's publicist Stan (Wayne Knight) sees Bugs and Daffy return to Tune Land and follows them, and stays to support Michael, whose team will be called the Tune Squad.Despite Michael's leadership, the Monstars dominate the first half of the game. After sneaking into the Monstars' locker room and being detected despite hiding in a locker and scorched as a result, Stan informs the Tune Squad that the Monstars stole the talent from the NBA players. Bugs then motivates the team with a "special drink", and the Monstars' commanding lead is reduced to a significantly smaller margin. Seeing Swackhammer angry that the Monstars did not steal Michael's talent, Michael takes the chance to raise the stakes. If the Tune Squad wins, the Monstars must give the NBA players their talent back, but if they lose, then Swackhammer is to spare the Looney Tunes in exchange for Michael. He readily accepts it and Bugs tries to talk him out of it, all the while being aware of what it means if Michael is subjected to humiliation on Moron Mountain for all time.As the game resumes, the Monstars, under orders from Swackhammer, begin playing even dirtier than before. As a result, the Looney Tunes are injured, one by one, until only Michael, Bugs, Lola and Daffy are left, leaving them short one player. Reluctantly, Michael puts Stan in the game, and though he is quickly taken out of action, the Monstars' lead is now down to one. Marvin The Martian, who is the referee, tells them that if there is no fifth player, the team will forfeit the game. At the last second, Bill Murray (whom Swackhammer incorrectly identifies as Dan Aykroyd, his Ghostbusters co-star) appears in the stadium and joins the team, breaking the fourth wall along the way.With only seconds left, Bill pulls some clever manueuvering and gets the ball to Michael. Extending his arm to superhuman lengths (since the laws of physics work differently in Tune Land), Michael makes the basket and wins the game. He helps the Monstars realize that they're bigger than Mister Swackhammer, who confronts them for losing. Fed up with their abusive boss, the Monstars tie him up to a rocket and send him to the moon. At Michael's request, they reluctantly return the stolen talent to the other players by transferring them to a basketball, which is how they stored the stolen talent earlier in the film. This reverts the Monstars back to the tiny Nerdlucks. Refusing to return to Moron Mountain, the Nerdlucks decide to stay with the Looney Tunes, who only agree if the Nerdlucks can prove themselves to be 'Looney', which they arguably complete on the spot.Afterwards, Michael returns to Earth in the Nerdlucks' spaceship, where he makes a dramatic appearance at a baseball game to the cheers of the audience, despite being late. The next day, Michael gives the stolen talent back to the NBA players, who immediately regain their lost skills. Michael is later prompted by his rivals to return to the NBA, mirroring his real-life comeback with the Chicago Bulls.
- Ash Ketchum, Pikachu, Misty, Togepi, Brock and the Pokemon gang, Simba, Nala, Timon, Pumbaa, Zazu, Kovu, Kiara, Ma, Uncle Max, Rafiki, Littlefoot, Cera, Ducky, Petrie, Spike, Chomper, Ruby, Guido, Grandpa Longneck, Grandma Longneck and the Land Before Time Gang, SpongeBob SquarePants, Patrick Star, Squidward Tentacles, Sandy Cheeks, Eugene Krabs and the gang, Bloom, Stella, Flora, Musa, Tecna, Layla, Stan Marsh, Kyle Broflovski, Eric Cartman, Kenny McCormick, Jean-Bob, Speed, Puffin, Terk, Tantor, Louis, Ray the Firefly, Genie, Iago, Sebastian, Baloo, Bagheera, King Louie, the Vultures, Jiminy Cricket, Mickey Mouse, Donald Duck, Goofy, Kenai, Koda, Rutt and Tuke, Fu Dog, Roger Rabbit, Woody, Buzz Lightyear, Charlie Barkin, Itchy Itchiford, Jack Skellington, Chanticleer, Owen, Izzy, Bowser, Mistress Nine, Bowser Jr., Ranamon, Oogie Boogie, Bob the Tomato, Larry the Cucumber, Junior Asparagus, Jimmy and Jerry Gourd, the Powerpuff Girls (Blossom, Bubbles, and Buttercup), the Rugrats Gang, Carly Shay, Sam Puckett, Alvin, Brittany, Bobby, Cindy, Oliver, Freddie Benson, Spencer Shay, Gibby, the Muppets (Kermit the Frog, Miss Piggy, Fozzie Bear, Gonzo, Rizzo the Rat, Waldorf and Statler, Sam the Eagle, Animal, and the Electric Mayhem), Popeye, Olive Oyl, Popeye's Nephews (Peepeye, Poopeye, Pipeye, and Pupeye), Scrooge McDuck, Huey, Dewey, Louie, Webby, Launchpad McQuack, Chip and Dale, Lilo, Stitch, Pleakey, Jumba, Mario, Luigi, Princess Toadstool, Toad, Yoshi, Donkey Kong, Diddy Kong, Sonic the Hedgehog, Miles "Tails" Prower, Knuckles the Echidna, Amy Rose, Cream the Rabbit, Cheese the Chao, Shadow the Hedgehog, Rouge the Bat, Team Chaotix (Vector the Crocodile, Espio the Chameleon, and Charmy the Bee), Silver the Hedgehog, Blaze the Cat, Spyro the Dragon, Sparx the Dragonfly, Banjo and Kazooie, Barney the Dinosaur and the gang, Baby Bop, BJ, Riff, The Griffins (Peter, Lois, Chirs, Meg, Brian, and Stewie), Pocahontas, Meeko, Flit, Princess Aurora, Peter Pan, Tinkerbell, Terrence, Fawn, Rosetta, Silvermist, Iridessa, Vidia, Alice, Hercules, Phlioctetes, Pegasus, Phineas and Ferb, Isabella Garcia-Shapiro, Alex, Marty, Melman, Gloria, The Penguins of Madagscar (Skipper, Kolwalski, Rico, and Private), King Julien, Maurice, Mort, Taran, Princess Eilonwy, Fflewddur Fflam, Gurgi, Jesse Greenwood, Elvis, Randolph Johnson, Nadine, The Goonies (Mikey Walsh, Brand Walsh, Mouth Devereaux, Data Wang, Chunk Cohen, Andy Carmichael, Stef Steinbrenner, and Sloth Fratelli), Aladdin, Princess Jasmine, Abu, Yogi Bear, Boo-Boo Bear, Snagglepuss, Huckleberry Hound, Quick Draw McGraw, Augie Doggie and Doggie Daddy, Wally Gator, Magilla Gorilla, Top Cat, Peter Potamus, Scrooge McDuck, Huey, Dewey and Louie, Webby, Tom, Huckleberry, Becky, Scooby-Doo, Shaggy Rogers, Fred Jones, Daphne Blake, Velma Dinkley, Bugs Bunny, Daffy Duck, Woody Woodpecker, Ttark, Rex, Woog, Elsa, Dweeb, Fievel Mousekewitz, Tiger, Tony Toponi, Tanya Mousekewitz, Yasha Mousekewitz, Papa Mousekewitz, Mama Mousekewitz, Kids World's Adventures Team, Hubie, Marina, Rocko, Makunga, Creeper, The Machine, The Fratellis (Ma Fratelli, Francis Fratelli, and Jake Fratelli), Abis Mal, Dick Dastardly, Muttley, Injun Joe, Flintheart Glomgold, The Beagle Boys, Drake, Warren T. Rat, and Cat R. Waulthe Queen of Hearts, Dr. Eggman, Mojo Jojo, Him, Fuzzy Lumpkins, the Gang Green Gang, the Scallions, the Bad Apple, Carface, Killer, Scar, Shenzi, Banzai, Ed, Emperor Zurg, Jafar, Maleficent, Myotismon, Lord Rothbart, Shere Khan, Cruella De Vil, Ursula, Clayton, Pete, Dr. Facilier, the Grand Duke of Owls, Syndrome, Fat Cat, Bowser,Mistress Nine Bowser Jr., King K. Rool, Dr. Ivo "Eggman" Robotnik, Scratch and Grounder, General Specific, and Private Public, Sheldon J. Plankton, Heather, Ichy and Dil,, Mojo Jojo, Ojo Tango, Rocko Socko, Baboon Kaboom, the Gogo Patrol, Hota Wata, Cha-Ching Cha-Ching, the Doot Da Doot Da Doo Doos, Hacha Chacha, Blah-Blah Blah-Blah, Killa Drilla, Bonzo Bango, Rolo Ovo, Cruncha Muncha, Wacko Smocko, Pappy Wappy, Him, the Rowdyruff Boys, Fuzzy Lumpkins, the Gang Green Gang, the Scallions, the Bad Apple,Team Rocket (Jessie, James, and Meowth), and the bad guys will guest star in this film.