The first season of Marvel's Avenger's Assemble comes to a rousing conclusion this Sunday, May 25th, on Disney XD at 9am EST/PST. In "The Final Showdown" there is a special appearance by villain Thanos - marking his first appearance in a Marvel Animation series on Disney XD.

Log Line: With the Tesseract now in the hands of the Cosmic Skull, the world is in catastrophic peril. Iron Man realizes teaming up with the rest of the Cabal might be their only chance for victory.

Here's an exclusive clip from the final episode.