The Massive

"Noticed that? This is a flagship for the Irken Empire. They called it the Massive. Can't you believe it's so big that it could transport the most importent people in the Irken Empire?"

--Su Ji-Hoon, Coming in Peace

The Massive is the appropriately-named giant flagship of the Irken Armada, and is escorted by many ships at all times. It is always surrounded by smaller ships, except in Invader Zim episodes, "Backseat Drivers from Beyond the Stars," where the Massive was dragged away from its fleet through a hacking by Zim; and "The Nightmare Begins," in the ending where Zim reported in to the Almighty Tallest.