Gaz

Gaz is the menacing younger sister of Dib, and one of the supporting characters in Invader ZIM. She is also the daughter of Professor Membrane, although it would have been revealed that Dib or perhaps Gaz as well are actually biological creations of the Professor, and not his biological children in the conventional sense. However, this has yet to happen within the series for Dib; but it still has not been confirmed if Gaz was a biological creation according to the writers or Jhonen Vasquez himself.

Gaz was voiced by Melissa Fahn in the original English version, and by Haruhi Terada in the Japanese dub. In the German dub she is voiced by Yvonne Greitzke.

She also plays a much bigger role in the Invasion series (a sequel to Invader Zim), taking over her brother's role as the deuteragonist with Zim and Dib sharing the role of the protagonist with Will taking Gaz's former role as the tritagonist.

Appearance
Though her dress style is reminiscently Gothic in appearance, she has, oddly enough, never established to be an actual goth. This was even stated by Jhonen Vasquez himself. Coincidentally, Gaz's clothing style bears a strong resemblance to that of Pepito the Antichrist (the son of Satan and a beautiful Christian woman), another creation of Jhonen's. Around Gaz's neck is a necklace in the shape of a stylized human skull. When she was younger, she still wore a black dress but had a bow in her hair, so it's unknown how she acquired her necklace.

The most unique characteristics about Gaz are her hair and eyes. Her purple hair is cubic and fashioned into five spikes, and takes on the ominous appearance of a mouth with fangs (actually a stylized bob cut). Also, her eyes are almost always closed or squinting, but when they are open her eyes are an amber color. In the Pilot, her eyes are blue with the exception of being brown/amber in one scene.

In season two of the show, Gaz's head was remodeled to be more angular, like her brother's head, when facing forward towards the camera, rather than having a round shape (though she had the rounder shape when she was younger). Her head seems to be large compared to normal human beings, but she accuses Dib (like almost every character) of having a big head. As the series goes on, she gets taller, and even has some facial changes, but her voice doesn't change much. However, her voice as an older woman will sound exactly like the voice of the battery store clerk in Game Slave 2.

Personality
Gaz is best known for her psychotic, anti-social and dark nature, along with her obsession with pizza and video games. When she isn't eating pizza or playing her Game Slave, Gaz typically just beats on Dib because of his talking (which enrages her) and appears to enjoy doing so. Although she is almost always grouchy and unhappy, her few interests have been known to coax a more positive side out of her, and in Battle-Dib she was friendly to the security guards at her father's television studio and said to her brother in a relatively cheery tone, "I thought I'd help you out", even after swearing revenge on her brother for stealing the last pizza slice.

Gaz, like most modern children, loves to play video games on her Game Slave, and has an obsession with Poop Cola and pizza. If anyone comes between herself and one of these things, she has a tendency to vow revenge, and make things very unpleasant for them. A prime example for this can be seen in the episode Game Slave 2, in which a hyperactive boy called Iggins took the last Game Slave 2 in stock at the mall. In return of this, Gaz stalked and terrorized Iggins until he surrendered the Game Slave 2 to her.

Her future self's personality
As the empress consort of the planet Irk, Gazlene now acts calm, reserved, patient, caring and regal, and unlike her brother, is experienced in grace and poise. She dearly loves her husband Zim with all her heart, and their children as well. She rules alongside ZIM in jure maritus.

Role in Invader ZIM
Gaz is the only one, with the exception of Dib, to realize that Zim is really an alien. In Bloaty's Pizza Hog, she replied to Dib's comment that Zim was trying to enslave all mankind replying with "but he's so bad at it". Another example can be seen in Gaz, Taster of Pork where she acknowledged Zim's an alien and says that "he's too dumb to take over the world".

On occasion, she has bailed out her brother, but only when it convenienced her, like in Bloaty's Pizza Hog and The Most Horrible X-Mas Ever.

Although she usually plays only a supporting role as the unwilling sidekick to Dib, her obsessive-compulsive brother, she has been the main subject in three episodes:
 * In Game Slave 2, Gaz attempted to buy the Game Slave 2 handheld device, and ruthlessly terrorized a kid named Iggins when he made off with the last one in stock.
 * In Bloaty's Pizza Hog, she proved that she'll do anything to eat out at Bloaty's, even rescuing her brother from Zim's clutches.
 * In Gaz, Taster of Pork, the episode chronicled the events that ensued when a mishap with one of Dib's spelldrives caused her to be cursed to a fate of tasting nothing but pork.

However she serves as the deuteragonist in the Invasion series (the sequel to Invader Zim) as she plays a much bigger role as Zim's ally and potential love interest. Her personality however will be the same as it was in the original series, being the same indifferent, cynical and psychotic girl she was always portrayed as.

Episodes

 * Pilot
 * The Nightmare Begins
 * Parent Teacher Night
 * Bestest Friend (cameo)
 * NanoZIM
 * Dark Harvest
 * The Wettening
 * Career Day (cameo)
 * Battle-Dib
 * Planet Jackers (voice cameo)
 * Rise of the Zitboy
 * Bloaty's Pizza Hog
 * Bolognius Maximus
 * Game Slave 2
 * Battle of the Planets (voice cameo)
 * Mysterious Mysteries
 * Abducted (cameo)
 * Future Dib
 * Lice
 * Dib's Wonderful Life of Doom
 * Tak: The Hideous New Girl
 * Backseat Drivers from Beyond the Stars
 * The Voting of the Doomed
 * Dibship Rising
 * Gaz, Taster of Pork
 * The Most Horrible X-Mas Ever

Abilities
Throughout the show, it is demonstrated, but never actually said, that Gaz has amazing powers. Her powers include: the ability to fix, pilot, manipulate, and in general control anything electronic, the ability to get any place she needs, the demonic ability to levitate on pure rage alone, to create fires at will, umbrakinesis, to generate spookiness in a tangible manner, shroud, etc. She is also shown to be capable of using Irken technology and her piloting skills seem to be on par, if not greater than Zim's, as she was able to pilot one of his ships with ease.

It is possible that these abilities, being completely unnatural, could actually be a result of her being a genetic experiment of Professor Membrane, just as it is rumored that her brother is (it is currently unknown if Gaz was Professor Membrane's creation or his biological child). She, despite her demonic nature, has a sort of connection to the holy, as shown in Game Slave 2, when upon getting her game back, the stormy night turned to a bright sunny day, and her hair returned to its natural shape. She also commented on how "the rightful order has been restored". In Mopiness of Doom, she similarly states, "All is right with the world again". These were obvious references to horror movies such as The Ring and The Grudge, which also contained considerably creepy girls, as well as the plot of Game Slave 2, which somewhat parodied the aforementioned movies.

Facts of Doom

 * Her voice actress, Melissa Fahn, has confirmed in the commentary for The Most Horrible X-Mas Ever that Gaz actually can show positive emotions and love others; she just does not like people interfering with her life and slightly has a big ego (much like Zim) and thinks she's better than others sometimes, hence her rotten attitude and demeanor around everyone she makes contact with. Melissa also confirmed in the same commentary that Gaz is the smartest character, even more intelligent than her own father.
 * In the episode Dark Harvest, Gaz claimed to have a Squeedly-Spooch. Her comment is most likely a retort to Dib's comment about Zim's Squeedly-Spooch.
 * The following episodes in which Gaz smiled were Parent Teacher Night (while snickering at Zim and Dib's misfortunes), The Wettening (before dropping her water balloon on Dib after Zim's watery victory against him), and Gaz, Taster of Pork (while she attempted to torture Dib with her robotic toys, and mentioned that she had programmed them to feed off of human flesh). She also smiled several times in the Pilot, but, given the many differences and inconsistencies seen in the "episode", its canonicity is called into question.
 * Her demonic nature, her attitude, her powers, constant abuse of her brother and misanthropic demeanor has caused controversy from Christians and the magazine Christian Parenting Today. In contrast, her voice actress Melissa Fahn has a very pleasant demeanor (as revealed in The Voices of Zim when she smiles and laughs during her interview), and she confirmed that she can show positive emotions. However, Jhonen has not made any comment on the controversy as of late, nor has Melissa.
 * Ironically, Fahn previously voiced the eponymous character in the Hello Kitty animated series, and she also voiced several characters in Ren and Stimpy.
 * Gaz's full name is Gazlene, a play on the word gasoline, but was never mentioned in the series. The play on words fits her personality rather well; like gasoline when ignited, Gaz has a very fiery temper when provoked.
 * Gaz is ambidextrous. She can be seen drawing with her right hand in The Wettening and with her left in Bloaty's Pizza Hog. During her coronation with Zim, she holds the Empress's Scepter with her right hand and the Empress's Orb with her left hand.
 * Her eyes are brown/hazel, although they were supposed to be light blue as they were in the Pilot. A coloring error led to her current eye color of amber/hazel.
 * In early episodes, her height occasionally changes; possibly due to some animation errors on the part of the artists. She is sometimes seen taller in her surroundings and other times shorter. The shape of her head also can be seen as angular or round in different episodes. However, she is still described as Dib's younger sibling.
 * In an image on Nicktoons's official site, Gaz is seen sitting playing her video game in Zim and Dib's classroom in front of Ms. Bitters. Though, Parent Teacher Night and Gaz, Taster of Pork notably explain that she is in Mr. Elliot's class.
 * During the Intro, Gaz breaks the fourth wall by putting her hand on the screen and brusquely shoving it aside.
 * Gaz was seen in two of Snafu's webcomics: PowerPuff Girls Doujinshi (as a cameo) and Invader Zim: Manifest Doom, where she was one of the main characters.
 * According to head writer Eric Trueheart, Gaz was going to align herself with the Irkens in a sketchy plot for Invader Dib, the "true" ending to the series. She would have encouraged Zim to continue fighting in his vision of seeing his own people dying (hiding her identity in a cloak and hood until the time is right, with only her eyes visible in the shadows), and afterwards she would team up with him to put an end to the fighting. After Zim is declared the next Tallest, she would move to Irk with Zim and join him in ruling the planet as his consort. She now wears Miyuki's Crown.
 * Gaz is a playable character in Nicktoons: MLB alongside Zim, though how they got to be partnered together is unknown. Best used as a pitcher, her throw is one of the fastest in the entire game; her throw leaves a trail of skulls in the same designs as the ones from her part in the show's intro scene. Her clothes are the same as in the show, only her dress has pinstripes and she wears a red baseball cap that transforms into a first baseman's helmet when she is at first base. In these concept sketches by Aaron Alexovich, in the series she was going to actually wear a helmet that would cover her hair.
 * Since Gaz's origin was not mentioned by Jhonen Vasquez or the writers of the series, there are only speculations of her being a biological experiment (like her brother Dib) or a natural born child. There are also speculations of her having a mother based on information from fansites and other web pages. A video from InvaderCon also gave some information about this when someone asked Jhonen who Gaz's mother was.