Sinister Rivalry
E1
When downtown turns into the site of the bug-battle of the century (insects vs. arachnids), it's up to Ty and Abby to take down Insectiva and her hated twin sister, Arachnidia (after all, arachnids eat insects).
Flushed Away
E2
When alligators start showing up in people's toilets, doing your business becomes risky business. Meanwhile, inventor T.P. Skinner starts selling the Gator-Guard 5000, a gator-in-the-toilet trapping system, so Abby considers him a prime suspect...or is he?
Vertigo A Go-Go
E3
Lance Boil has planted a nanodevice in Abby's ear, and those of many other students, causing serious vertigo, as well as complete control of their every move. Ty's refusal to clean his own ears has led to a buildup of ear wax, making him the only one immune to Boil's weapon.
Sloppy Joe to Go
E4
Sloppy Joe opens a fast-food joint with portions so big that half the food is thrown away, creating a garbage overload in the city.
Hairless Whispers
E5
The Grossologists tangle with a former hair stylist who has a space satellite that could make everyone in the world go bald.
Stinko
E6
Sloppy Joe creates a body-odor epidemic during a heat wave.
Mold Monster
E7
Roger Pinkeye uses smelly cheese to create a monster out of mold.
When Allergies Attack
E8
Lance Boil drops an allergy bomb at a carnival.
Pussed Off
E9
A major case of acne spreads through Ringworm High.
Ask the Dust Mites
E10
Lab Rat invents a shrink ray...but in the process accidentally creates giant dust mites, who fall to the control of Arachnidia. Attempting to correct his mistake, he only makes things worse by accidentally shrinking Paige.
Turd Wars
E11
An army of giant dung beetles has stolen all the manure from nearby farmland (with Sloppy Joe along for the ride), as part of Insectiva's evil plan. Meanwhile, Abby is forced to serve as the school's Hall Monitor, and help keep it clean...but Paige is determined to make her task impossible.
Spa Insectiva
E12
An exclusive spa opens and customers are raving about its fancy bath products, but they're all bug-based and created by Insectiva, the insect queen.
Ain't Over Till the Fat Man Sings
E13
A disgraced opera star is set on revenge and plans to blow everyone away with destructive burps.
Candy Isn't Dandy
E14
A candy man comes to town with treats that cause bad breath.
Swamp Gas
E15
A mechanical swamp monster is causing power outages all over the city.
Squirm
E16
It's time for an Archer Family daughter/son and father/mother adventure while Ty and Abby take on extreme sports together with their friends Daphne, Chris, Emma, Zack and Dana, Petunia and Harvey take on a Motocross Championship
Let Them Eat Fruitcake
E17
Abby notices that holiday cheer is lacking during the Christmas season, especially with Sloppy Joe playing the local Santa.
New Recruits
E18
Ty and Abby recall their early days as Grossologists.
Pinkeye & the Brain
E19
Roger Pinkeye kidnaps Lance Boil, hoping to use him to get all the Grossology secrets.
Pinkeye's Revenge (Part I)
E20
Lance Boil and Roger Pink-Eye have teamed up, and they've got a plan. They're going to make Roger's dream come true; he's going to become a Grossologist. All it's going to take is an army of rats and an evil clone of Abby! Too bad Roger's not watching out for the Lance Boil double cross!
Pinkeye's Revenge (Part II)
E21
With Abby a prisoner, her evil clone working an inside job at the Bureau of Grossology, and Ty and Lab Rat off the team, Lance Boil looks unstoppable! Now there's only one person left who can stop him, Roger Pink-Eye!
Fangs a Lot
E22
Little pet snakes are sold all over town before they morph into deadly beasts.
Hirsute Yourself
E23
Frederick Follicle returns to town, bringing a hairy epidemic with him.
Pucker Up
E24
Insectiva and Sloppy Joe are determined to ruin Valentine's Day.
The Fart Side of the Moon
E25
Fartor returns with an explosive plan to send a gassy meteor on a collision course with Earth.
Night of the Living Roadkill
E26
Darko Crevasse returns with an army of zombie roadkill animals, and he's on a mission to ruin Halloween.