Melissa Fahn

Melissa Fahn played Gaz as well as other minor characters in Invader Zim.

Fahn primarily provided the voice for Dib's sister Gaz. Jhonen Vasquez has said she was cast in that role because she naturally sounded like a little girl.[1] Aside from Gaz's voice, she is also credited for being the voice of other minor characters, including Mongo Slunchy's little brother, Tess, and newborn Zim. She can be heard discussing her roles in the show in both a DVD interview and the DVD commentary, most notably in the episodes Game Slave 2, Gaz, Taster of Pork, and The Most Horrible X-Mas Ever.