The basic idea of episode 4A—“Germs”—is that Zim tries to defeat the Germ menace; after watching a human sci-fi movie, inspired by the works of Orson Well, where the alien invaders are brought low by germs, Zim rushes to his lab to confirm his uneasy suspicions. Once confirmed with the help of some microbiotic goggles, Zim unleashes all of his pent up anxieties in decimating the germ menace.
The episode is amusing because of the layering: Zim, the invader, turns to invading the world of germs through his incessant disinfecting; an all too real representation of Zim’s violence made all the more acute when a lone anthropomorphized germ, after being sprayed by Zim’s anti-germ spray, calls out “why?!” before being sprayed one final time (rather violent for a kid’s show!). So, in a way, Earth fights back without even realizing it because, whether or not the germs actually have an effect on Zim, it is clear that he anxiety of them possibly having an effect is alive and well. All though only a small twist to the War of the Worlds formula, its subtlety is amusing all the same.
Obviously, Zim eventually runs out of his disinfectant. While frantically rushing to the store in an effort to buy more disinfectant, he chases Zim into a McMeaty’s restaurant. There he discovers that the meat used is completely immune to germs. After being told a story of how “space meat” was used to survive trips into deep space, he appropriates all of the meat, covers himself in it, and returns to school coated in the fake, napkin derived product which he looted from the eatery.
So the subtle twist goes deeper. Not only does Zim win in his war against germs, but he is also made a fool of, thus jeopardizing his mission.
As I said, the layering here is an amusing spectacle to disentangle. Though Zim emerges triumphant in his anti-germ struggle, the attempt on him by germs is but one of two counter-colonization attempts made by Earth; the second is their cultural difference: Zim unwittingly bathes himself in meat ignorant of the fact that that is not what culturally acclimated youth do with their bodies. So the counter-attack by Earth comes on two fronts: one—germ—two—culture, and it is smartly handled in a way which pays homage to Orson Wells without it appearing as so. If we wanted to take this literally, then we could say that this germ culture is literally just that as represented by humanity, a culture of germs.
I always found this episode amusing because it displays Zim at his most incensed but also paranoid. GIR, meanwhile, is seen as hanging out with wealthy pigs, who evidently drive motorcycles and bring a new meaning to the term capitalist pig. It is an odd episode that brings out the zany nature of the Zim universe. It reveals the everyday determination of Zim to go all-out in his quest to understand and subjugate humanity. Anytime it is simply Zim trying, and usually failing, to get the upper-hand on the humans, the watcher can expect some laughs. If, for no other reason than him failing so utterly and completely.