sentences:  Six of the completed second-season episodes initially went unreleased.These episodes would first appear on DVD in 2004 and later made their television debut on Nicktoons from June 10 to August 19, 2006.On December 24, 2011, the series' pilot made its television debut on Nicktoons (it had previously only been seen on DVD) after an eight-hour marathon and followed by the result of Nicktoons' "Girreatest Zim Moments" online poll.