Invader Zim is the one who created Filler Bunny to keep the suspicious humans distracted and happy while he continues his plan of world domination. == Gaz and Dib were created specifically to defeat Tak and Zim. == 11 years before the events of the show, Professor Membrane somehow (possibly by time travel or prophesy device) learned of a future where two aliens invade the earth and their rivalry to claim credit for dominating the earth destroys the planet. In order to prevent this, he creates two children, at least one of which using his own DNA as a basis (Dib), each specifically designed to contrast their respective alien counterpart. Thus why Gaz is more powerful than Dib: because Tak is a greater threat.