So for those of you who don't know, Invader Zim is about Irken alien Zim, a failure and embarrassment to his kind and their army of Invaders, who annoys the Almighty Tallests (the leaders) into giving him another mission. They send him as far away as possible, to planet Earth, on a faux-mission just so they can get rid of him. They also give him a malfunctioning robot henchman named Gir, often random and stupid and non-helping in any and all matters. So Zim goes to Earth, forms a costume (two contact-like human eyes and a bit of hair), and enrolls in ‘Skool', going to the bat-like Ms. Bitters' class, and is immediately noticed as an alien by paranoid paranormal investigator (and fellow classmate), Dib. Dib constantly tries to foil Zim's plans and prove to all of his incredibly stupid classmates and other peers, including his video-game loving sister Gaz and super-genius father Professor Membrane, that Zim is, in fact, an alien. Randomness ensues, often involving pigs, moose, and Mexican food.
First, for an animated show, I must talk about the animation, of course. It's a good mix of bizarrely hand-drawn animation with a touch of 3D animation. The characters often have big eyes and exaggerated features, such as tiny bodies with enormous heads (in fact, there's a running joke about how huge Dib's head is in comparison to everybody else, when it's really pretty much the same size). There are some really amazingly drawn shots, and some really basic drawing, sometimes both plastered right against each other (and sometimes self-mocking because of it).And the show is very dark, almost to the point of disturbing, which I believe is why it didn't last very long. And not just because of some of the animation and how things are drawn, but in the story-arcs of certain episodes and things that occur. For instance, there's an episode in which Zim attempts to be more human for a visit to the nurse's office by stealing all the students' vital organs. He ends up a plump blob full of human organs, with intestines and such falling out of his mouth, while the rest of the student body drones along zombie-like (and a darkly hilarious moment in which Gaz plays her video game, which had replaced one of her organs, through her skin as if it were nothing). But not all of the humor is dark. In fact, a lot of the humor is completely random and comes from the dialogue. For instance, pretty much anything Gir does or says is hilarious (because it never makes any sense and just comes from left field). And even when the show seems like it is trying too hard, it doesn't come off as such (as one scene in which Zim is talking to Dib and states "You're nothing Earth boy! Go home and shave your giant head of smell with your bad self!"). There are too many random moments to even pick any few favorites to list here. It's just something you'd have to experience on your own. But it is laugh-out-loud comedy, as I often found myself doing just that.
So from there, I suppose I could discuss the characters of the show. They're all amazingly fun characters, and even after I finished the entire series, I had trouble picking out an all-time favorite. They all just had their own qualities: Zim, who is constantly screaming and acting overly mighty and powerful (when he's really not); Gir, who is just silly and random; Dib, who is the supposed ‘hero' of the show, though he's quite inept at what he does; and Gaz, who couldn't care less about any of this. Honestly, Dib has the biggest character growth throughout the series. He starts off always failing to stop Zim and getting increasingly frustrated about it. As the series starts to come toward its end, he's still boggled as to how nobody can notice that Zim is an alien, but if he fails at whatever it is he's trying to do in that episode, he just shrugs it off as another to add to the list. There's even a moment when he's screaming a big "NOOO!" moment, but then just cuts it short with a half-hearted "whatever" and lays down to go to bed. Gaz, on the other hand, is the most interesting, and possibly one of the darker characters. She hates pretty much everybody, and the Gaz-centric episodes are always fun, because her character becomes incredibly creepy and sometimes frightening. In other words, while some shows have a large cast with only a couple good characters, this has a good ensemble of characters who can each hold their own (and often do).
The stories are often ridiculous and random, but that just means they fit the feel of the characters and animation perfectly. There are episodes from organ stealing to time travel to zits to Santa Claus. There are even episodes that have some fun social commentary in them, like "The Girl Who Cried Gnome," in which a little Girl Scout-type girl gets her foot stuck in a gopher hole, and all of the town media shows up to document the event to the world as if it were a baby caught in a well and the end of the world resided on getting her free. What the series loves to do is make huge moments out of nothing, which is where even more of its humor resides. And another bonus is that later in the series, episodes begin to connect themselves together, so each one isn't completely separate from each other like most cartoons these days. Older episodes are referenced in order for characters to make arguments in things they've done, and in an episode in which Dib gets an Irken ship, he has it in basically every episode from then on, trying to fix it so that it'll work for him. That's always a nice touch, and much more on the level of anime than normal American cartoons.
So overall, I'd recommend the show if you're into disturbing and random comedy. Its dialogue is even more random than something you'd find in an episode of Family Guy or Futurama, but at the same time, it can be kind of witty. The show definitely isn't for those who don't have a darker sense of humor, but if you do, you should check it out. There are only 27 episodes total, some of which were never aired on TV (I believe) and can only be found on the DVDs. It just goes to show you (along with Avatar: The Last Airbender, another show I plan on reviewing soon) that Nickelodeon is capable of producing some good cartoons that adults can easily enjoy. So yeah, watch this show or you shall feel doom rained down upon your doomed heads! (I'm gonna sing the doom song now! Doom doom doom doom doom doom doom doom doom...).