When the Roboparents present themselves as zookeepers in order to prove to the other Skoolchildren that they have jobs, Zim has to quickly create a zoo outside his base in order to maintain his cover. However, the other children are unimpressed and grossed out by the hastily created fake animals of the zoo, and accuse Zim's "parents" of being grifters. Dib, meanwhile, takes photos of the fake animals to the police; when they refuse to listen to his explanation of Zim being an alien, he repeats the grifter rumor, which they take seriously.
Krom and her unit are subsequently dispatched to "Zim Zoo", where a quick investigation confirms that the animals are fake. Krom gives the Roboparents a stern warning, giving them one day to replace the fake animals with real ones. When she and the ZCD return the following day, Zim's efforts to spruce up the zoo fail to pass inspection, and Krom places the Roboparents under arrest.
However, despite Dib's expectations, Krom doesn't arrest Zim as well, seeing him as an innocent child caught up in his parents' crimes. So, after confirming that he has someone else to take care of him, Krom carts the Roboparents off to jail, while warning Dib to never bother the ZCD again.