Invader Zim When Did It Air? March 30, 2001 to December 10, 2002 Why You Should Watch Now: The 2000s were also a very experimental time, and Invader Zim kicked off the decade in style. One of the ...

And now, thanks to the folks over at Hasbro, you can re-watch the first 15 episodes of the original series for free on YouTube ... cropped up years later, the cartoon — and its namesake action ...