Invader Zim Episode 24 - Battle of the Planets Episode Title:Battle of the Planets.Episode Description:Zim is surveying the other planets in the solar system and discovers that Mars has actually been converted into a space vehicle by the previous inhabitants of the planet. Zim decides to use the planet to crush all the lifeforms on Earth, but Dib discovers his plan and attempts to stop him. Dib uses Mercury, which has also been converted to a vehicle, and the two use the planets to battle each other in space. Zim, attempting to lose Dib goes into the asteroid belt but completely loses control. Dib, who thinks he's won, then realises that GIR had destroyed all his evidence recording equipment. This is the second double-length episode of Invader Zim. This episode was planned to be the first season finale until Nickelodeon ordered seven extra episodes for the season.[8] This episode was voted one of the "Top 5 Best Invader Zim" episodes by ToyFare.[9]