When Septico's long lost brother comes to visit, he's repulsed by the grossness of the Yuck Lab - until he accidentally gets turned into a poop loving housefly.
When Septico's college crush, Botany "expert" Egregious Flytrap visits the lab, the gang tries to impress her with various disgusting plants, not realizing she wants to use those plants in a diabolical experiment.
The lab gang is left in charge of an annoying little girl with a tummy ache, as they scramble to prepare their submission for the World Yuckology Expo.
Leonidis' locks down the lab when his favorite stinky sandwich gets stolen, so Septico has to expose the gang to various stinky animals to find the culprit.
When it's revealed that Durp-E is secretly keeping a pet rat in the Yuck Lab, everyone is shocked as to whom the cringing, shrieking aversion to them is.
Septico and the gang try to stop the O'Cleans from destroying the world's Mite population by creating an ad campaign to show that microscopic mites are actually cool.