Professor Membrane

Professor Membrane is the father of Dib and Gaz, but he has very little time for his offspring, being one of the most famous and important people on Earth. The Professor, as he is often called, is rarely at home, so he supervises his kids in the form of a floating monitor, which often spews out pre-recorded reminders that are often way out-of-date. Expectedly, Dib and Gaz refer to him as Dad.

Personality
Although his parenting skills seem to be missing in action, he really does love his kids, taking time at least once a year for dinner together—and always remembering to activate the food monitor. However, Membrane is somewhat ashamed of his son's belief in the paranormal, refusing to call it a "proper" branch of science. However, he believes Dib's obsession is just a phase (or as he speaks of it, "temporary insanity"), that Dib will grow out of, and allows his son to do as he pleases to an extent. On occasion, Membrane is so preoccupied with work that he fails to recognize his own kids (i.e. not recognizing Dib when he comes backstage in "Battle-Dib").

Appearance
Professor Membrane's appearance has not developed much since he was a child, other than his increased height. He wears a white lab coat, purple gloves, and big black boots. His eyes are never clearly seen due to him wearing goggles. Dib looks a lot like his father, both sharing black hair styled in similar scythe-like shapes.

It has been confirmed that Professor Membrane, as well Dib and Gaz, is a very pale Mexican.

Abilities
In "The Most Horrible X-mas Ever", Membrane seems to have incredible power, similar to that of Dib's power in the episode "Dib's Wonderful Life of Doom", when he blasts open the back door with an energy beam fired from his glove, although this is likely based more upon technology than any natural gift. Professor Membrane has also had a grudge against Santa Claus ever since he was a child; on Christmas day, instead of giving him twelve cases of Uranium-238 as he'd asked, Santa gave him a present overflowing with socks.

Role in Invader Zim
Membrane is based on many real-life scientists and inventors, such as Nikola Tesla and Stephen Hawking. He has a science TV show similar to Bill Nye the Science Guy, which requires the people in the audience to pass several tests just to sit and watch. He is somewhat of a celebrity, and was described in "Future Dib" as someone "without whom the whole world falls into chaos".

The Professor appears to be about 40 or so; his first name is unknown, but none is apparently needed; he is world-renowned for his contributions to human science, making breakthroughs in every scientific field, from genetics and neuroscience to disease research and engineering. Some of his most notable inventions include the hover helmet, the Perpetual Energy Generator (which was never put into use, due to heckling from the crowd) and Super Toast.

Had the series continued, it would have been revealed that Dib and maybe Gaz as well were not actually Membrane's birth children, but had been genetically engineered by the Professor, perhaps as an experiment. This may explain why Dib and Gaz seem to have superhuman powers, as well as the lack of a mother in the Membrane household. However, this idea was never brought to fruition.

In the comic series, Membrane is presented as more of an active parent, as he's seen spending more time having meals with and playing games with his children, in person rather than by remote. However, he's also demonstrated that he still prioritizes science over them -- in Issue 5, he agrees to help Gaz imprison Dib in an alternate universe ruled by gamers just because she says it's for science, and in Issue 16, he's happy to let Dib use an experimental fear siphon, even though he admits it's not ready for human use yet.

Facts of Doom

 * Professor Membrane's voice actor is Rodger Bumpass, who also provides the voice of Squidward on SpongeBob SquarePants.
 * Bumpass also portrayed Nightmare Bitters in "Halloween Spectacular of Spooky Doom".
 * TruthShrieker revealed that his last name actually is Membrane.
 * Professor Membrane (somewhat erroneously) believes that Zim is from another country rather than another planet (this could refer to the fact that "alien" is also a synonym for "immigrant").
 * He also said in one episode that if there truly were aliens in space then they would be too far away and believes that not one of them could travel the massive distance to our planet, completely unaware that Zim is an alien from space and that he survived the massive trip to Earth.
 * The Professor seems to have a deep and strong loathing for the fact that Dib actually successfully re-awakened the living dead and won't let Dib forget it, even though Dib said he was sorry.
 * He doesn't allow Dib to use his tools for his "para-science", as stated in the Halloween episode. This, however, is contradicted in "NanoZIM", when he allows Dib to use his nanoship.
 * The Professor has a lever built into his home to restore power to the entire City in the (apparently frequent) event that his son causes a city-wide blackout.
 * He has on a couple of times in the series called Dib "my poor insane son".
 * In "Battle-Dib", it's revealed in his autobiography that the professor's first sentient thought was "I will poop now".
 * The Professor calls Gaz his "funny child" and sometimes he even calls her "honey". He sometimes even calls her by her name — which he never does to Dib.
 * He knows that Dib's voice angers Gaz greatly, but still has her go up into his room to spend time with him and hopes that her company will help Dib become "less insane".
 * The Professor has a little handmade puppet version of himself and seems to have a talent for ventriloquism. However, this may just be because his mouth is covered by his clothing.
 * He's the creator of Super Toast and of the Perpetual Energy Generator (also known as P.E.G.).
 * In "The Most Horrible X-mas Ever", during a flashback when the Professor was a kid, he sounds as if he's already an adult.
 * In "Halloween Spectacular of Spooky Doom", he appears as a nightmare monster along with Gaz.
 * Melissa Fahn played Professor Membrane during InvaderCON 1, as Roger was not invited as a guest at the time.
 * Professor Membrane's name is based off of membrane, a thin, film-like structure that separates two fluids.
 * Professor Membrane may well be a very vain individual, considering how highly he talks of himself and his studies. Not only that, but he has a lamp of himself in his own home.
 * Professor Membrane has made it clear that he'll do anything if it's stated to be "for science", no matter how morally questionable. It's how he justifies imprisoning Gaz and turning her into a media freak in "Gaz, Taster of Pork", and in Issue 5, Gaz weakly using it as her reasoning for finding a dimension ruled by gamers and imprisoning Dib in it is enough to get Membrane to go along with it.
 * In Issue 16, he allows Dib to use an experimental Fear Siphon, despite admitting it's not safe for human use yet. Combined with the above mentions of doing anything "for science", this implies the Professor has a very loose set of morals.
 * This issue also shows that, despite being a man of science, he seems to be unaware that humans have already landed on the moon, as he states that the Fear Siphon's slurry could one day be used as fuel to reach the moon.