Invader Zim Returns - (Fan-made) - Spooked

Invader Zim, GIR, Dib (the human male 12 year old who saw through Zim's disguise and who tries to stop him from invading Earth), and Gaz (Dib's sister who is 11 and knows that Zim is an alien, but thinks that he is too stupid to invade Earth, so doesn't care) all get transported to a different world called The Nightmare Before Christmas filled with monsters, and turn into monsters as well.