When the Scooby gang are on a trip, they meet the Avengers, when the Mandarin threatens to wipe out America, and the Shredder is in league with them. And they work with the X-Men and the Ninja Turtles to stop them.


  • Scooby-Doo (Frank Welker)
  • Shaggy Rogers (Matthew Lillard)
  • Fred Jones (Frank Welker)
  • Daphne Blake (Grey DeLisle)
  • Velma Dinkley (Mindy Cohn)
  • Avengers:
    • Iron Man (Adrian Pasdar)
    • Captain America (Roger Craig Smith)
    • Thor (Travis Willingham)
    • Hulk (Fred Tatasciore)
    • Hawkeye (Troy Baker)
    • Black Widow (Laura Bailey)
    • Falcon (Bumper Robinson)
    • Spider-Man (Drake Bell)
  • X-Men:
    • Cyclops (Kirby Morrow)
    • Jean Grey (Venus Terzo)
    • Spyke (Neil Dennis)
    • Wolverine (Scott McNeil)
    • Storm (Kirsten Williamson)
    • Rogue (Meghan Black)
    • Beast (Michael Kopsa)
    • Shadowcat (Maggie Blue O'Hara) - when she accidentally lost control of her powers during a battle with Shredder, Killian plants Extremis inside of her power to fix the problem
    • Nightcrawler (Brad Swalie)
    • Iceman (Andrew Francis)
    • Colossus (Michael Adamthwhite)
    • Angel (Mark Hildreth)
    • Gambit (Alessandro Juliani)
    • Havok (Matt Hill)
    • X-23 (Brit Irvin)
  • Leonardo (Mike Sinterniklaas)
  • Raphael (Frank Frankson)
  • Michaelangelo (Wayne Grayson)
  • Donatello (Sam Riegel)
  • Mandarin (Oded Fehr) - the main antagonist, and Iron Man's arch-enemy, he has been setting bombs around the world
  • Suspects:
    • Aldrich Killian (Santino Fontana) - Daphne's ex-boyfriend, after she left to join the gang after their first mystery, he is the inventor of Extremis, Reason: Fred chooses him as a suspect because he believes he is stealing Daphne from him, the way he womanized Kitty
    • Maya Hansen (Kari Wuhurr) - Tony's ex-girlfriend, Reason: because of her research on plants.
    • SteamGlove (Tom Kenny) - Owner of Water Workers INC, Reason: because of the activity on the Water Pipes.
    • Captain Beast - ???, Reason: ???


  • Aldrich Killian (Santino Fontana) - Reason: He wanted give Tony what he gave him, desperation, since he couldn't meet him on the rooftop on New Year's Eve