Pretty sure that's
Rocket, a character created by the late, great
Dwayne McDuffie under his Milestone imprint. And if Rocket is there then you know
Icon can't be far behind. There's also a mystery fight between Superboy and what looks like another Superman clone. There's no Embed for the actual video but click the image below to watch it on the official DC Comics website.
Young Justice is an American animated television series created by Greg Weisman and Brandon Vietti for Cartoon Network. Despite its title, it is not an adaptation of Peter David, Todd Dezago and Todd Nauck's Young Justice comic series, but rather an adaptation of the entire DC Universe with a focus on young superheroes. The series follows the lives of teenaged heroes and sidekicks who are members of a fictional covert operation team called Young Justice. The team is essentially a young counterpart to the celebrity-level famous adult team, the Justice League. The main setting is the fictional universe of Earth-16, during a time period in which superheroes are a relatively recent phenomenon. The series debuted on January 7, 2011 with a two week reairing of the first two episodes, which originally aired as an hour long special on November 26, 2010. Young Justice premiered on September 9, 2011 on Teletoon, in Canada.
Young Justice is currently on a hiatus and will resume on March 3, 2012.