Bakugan

In the exciting new season of Bakugan, the VESTROIAN star system is made up of six planets each home to a different species of Bakugan.<br><br> Experimental weaponry causes the Bakugan to be transported to Earth, where humans welcome them, until teenagers start pairing with Bakugan and gain the ability to grow to giant size; during this time filled with fear, the Catastrophe takes place.<br><br> (Source: 9Go!)