He costarred in the 2009 film '' April Showers '' , a movie written and directed by a survivor of the 1999 Columbine High School massacre . He played Kyle , a misanthropic teenager in '' World 's Greatest Dad '' , with Robin Williams , and Peter Cratchit in the 2009 film adaptation of '' A Christmas Carol '' . He appeared in the comedy series '' Easy To Assemble '' , where he played a character named George . In 2010 , he appeared in the movie '' Machete '' , as well as the MTV movie '' Worst . Prom . Ever . '' which premiered May 10 . In 2012 , he co-starred in '' John Carter '' as Edgar Rice Burroughs
Columbine High School massacre
Columbine High School massacre
Daryl Sabara