Invader ZIM - Season 1 - Eps 1: The Nightmare Begins
Dedicated Irken soldier Zim is sent on a secret mission to Earth, where he disguises himself as an elementary-school student and gathers information about human beings. His plan is moving smoothly until an extraterrestrial-obsessed classmate named Dib takes notice of Zim's green skin and missing ears.
About Invader ZIM

Title: Invader ZIM
First Air Date: 2001-03-30
Last Air Date: 2006-08-19
Status: Canceled
Rating: 8.412/10 (from 388 votes)
Language: EN
Seasons: 3
Total Episodes: 46
Network: Nickelodeon
Genres: Animation, Sci-Fi & Fantasy, Comedy, Kids
Production Companies: Nickelodeon Animation Studio
Synopsis
Zim dreams of greatness. Unfortunately, though, he's hopelessly inept as a space invader. Desperate to be rid of the annoying Zim, his planet's leaders send him on a mission to infiltrate Earth, providing him with leftover, cobbled-together equipment. To their consternation, Zim succeeds in setting up a base on Earth and infiltrating human culture, posing as a human child as he plots the planet's downfall. Only Zim's archnemesis, Dib, recognizes that Zim is an alien, and of course, nobody believes Dib's claims.
Cast

Richard Steven Horvitz
Zim (voice)

Andy Berman
Dib (voice)

Rosearik Rikki Simons
GIR (voice)

Melissa Fahn
Gaz (voice)

Lucille Bliss
Ms. Bitters (voice)

Rodger Bumpass
Professor Membrane (voice)

Kevin McDonald
Almighty Tallest Purple (voice)