Johnny Test season 4

"Johnny's New Baby Sisters": Susan and Mary purposely revert themselves back into babies while the parents are out, and Johnny has to keep them safe from the irresponsible babysitter Gil; this interferes with a party he and Dukey had been planning and Mr. and Mrs. Test are mad.

"Porta-Johnny": Johnny tricks his sisters into letting him have teleporting powers by threatening to use water with green food coloring that he said that he mixed ingredients from the unstable cabinet. When they find out, Susan and Mary mess with the powers to get revenge. Later the twins accidentally get them caught in a middle of an art robbery.

"Join the Johnny Scouts": After Johnny lands his bike into a garbage truck, he becomes a Lady Bird Scout and tries to sell 1,000 boxes of cookies to get a new one. Little does he know, Sissy wants the bike as well, but for a better reason.

"Johnny B.C.": Johnny goes back in time in order to get a sloth bone for the twins, but when he returns he becomes a caveman, blowing off his grounding for selling Hugh's personal items and from leaving the house.

"Runaway Johnny": Johnny and Dukey run away when Johnny's parents say he's old enough to do chores but not old enough to watch PG-13-rated movies.

"Johnny on the Spot": Johnny steals a portable black hole, which later creates an early apocalypse.

"Dark Johnny": Johnny joins forces with Dark Vegan to get him back to his home planet.

"No Homework for Johnny": Susan and Mary build Johnny a robot in order to help him do his homework, but the robot ends up stealing things for Johnny.

"Papa Johnny": Johnny is tired of being annoyed and tied up by Hugh. So Susan and Mary switch Johnny and Hugh's brains after the two make a bet that involves taking on each other's lives.

"The Johnnyminster Dog Show": Johnny and Dukey try to get in a dog show which only allows purebred dogs.

"Johnny's Amazing Cookie Company": Susan and Mary make fortune cookies that come true, and Johnny sells them with the typical drastic results.

"Johnny's Big Dumb Sisters": The twins' latest invention accidentally blasts them into "Dumbville" thanks to Johnny right before their scholarship interview.

"Dukey Jeckyll and Johnny Hyde": Dukey drinks a liquid which makes him turn into a monster. To make matters worse, a dog catcher (and later Mr. Black and Mr. White) are after him.

"Johnny's Trophy Case": Johnny wants to get a trophy to put in his trophy case. He tries stuff that makes Hugh lose money and get less than $1,000,000. Susan, Mary and Hugh get obsessed with winning, so the three of them enter the Porkbelly River Jump-Off to win $1 million and a trophy. They win in the end, but Dukey destroys the neighbors house and bye-bye million dollars.

"My Johnny Guard": Johnny gets hired to stop Bling-Bling from kissing Susan, but Johnny turns on the sisters once Bling-Bling bribes him.

"Tom and Johnny": Johnny turns into a mouse for Susan and Mary, but when Mr. Mittens comes, things get chaotic.

"The Quantum of Johnny": Johnny tries to get invited to a party to stop a villain.

"Johnny Get Yer Gum": Mr. Whacko invents a new helium gum called Helio Bubble that lifts kids into the sky, and Johnny must save them.

"Old School Johnny": Johnny travels to 1845 when school was easier, but he gets stuck there due the power supplier for the Turbo Time Tea not being invented yet. The sisters and Johnny try to find outdated technology to power the tea house. First, they try the Great Fire of Prokbelly, but Dukey sabotages it. They, then try methane, but it takes 59 years to charge. More methane from the train is eventually obtained to power the machine and get back to the present.

"Johnny Degrees Below Zero": Johnny uses a device that the Test twins told him not to extend 5000 newtons, but he doesn't listen and creates a magnetic force field on the Earth which makes Porkbelly the new North Pole.

"Johnny Johnny": Black and White make Johnny and Dukey robots, but become corrupted and are now evil. They spit meatballs at Hugh, brake Lilas car, and trash the lab. The real Johnny and Dukey get framed for doing that stuff and for doing stuff around Porkbelly.

"Johnny Double Coupons": Johnny keeps attempting to ride down Suicide Hill, but Susan and Mary keep redeeming Johnny's coupons. 

"iJohnny": The twins upgrade Johnny's new cell phone. Later the phone becomes too intelligent and begins hacking government space missiles.

"Johnny vs. The Mummy": Johnny goes on a trip to the museum and uses a spray to bring the things to life, including a mummy.

"X-Ray Johnny": Johnny gets X-Ray goggles. Meanwhile, Zizlar tries to steal the Porkbelly library with a series of subterranean bombs.

"The Destruction of Johnny X": Johnny and Dukey decide to remain in super hero mode permanently, but they find being a superhero is more difficult than they think.

"Johnny Grow Your Own Monster": Johnny's mail order foam monster becomes a real monster once the twins swap the water with their glass of "side effects wicth was used to make the monster evolve".

"Who's Johnny?": When Sissy considers Johnny too gross to help her in a science project, he begs Susan and Mary to change his personality.

"Princess Johnny": Johnny poses as a princess in order to prevent a war. Meanwhile, Susan and Mary decide that they would like to act like normal girls.

"99 Deeds of Johnny Test": After getting his 99th detention, Johnny learns he must perform 99 good deeds or he will be sent to military school.

"Johnny's Amazing Race": Johnny and Dukey challenge his sisters, their friends, and their enemies to a survival challenge in which the winning team gets hundreds of dollars in gift certificates.

"Johnny Test in 3D": While the Tests go on vacation, Johnny sneaks Dukey into the hotel but they get kicked out and try to get back in the hotel room 3D and avoid the hotel manager that doesn't allow dogs.

"Guess Who's Coming to Johnny's for Dinner": Mr. Black moves in with the Tests after he embarrasses Mr. White at the dance contest auditions.

"Johnny's New BFF": Johnny's parents keep setting Johnny up with new friends. When those don't work out, Johnny reveals Dukey's intelligence. Later, Dukey spends more time helping Johnny's parents instead of playing with Johnny.

"Johnny vs. Bling Bling IV": Johnny once again has to protect Susan from Bling-Bling Boy who is determined to have her as his valentine.

"Johnny's Big Sisters' Smackdown": Susan and Mary both want Gil to go on a date with them, so they put up a wrestling match using rough guts (Susan uses Johnny's while Mary uses a lion's), but it leads to destructive results.

"Sunshine Malibu Johnny": Johnny goes to the beach to surf, but there are no waves, so Susan and Mary build a wave making machine and special surfboard for him. When Johnny turns it to Don't Even Think About It Johnny, a wave is sent to the beach, and they must send it to Australia.

"Johnnycicle": Johnny and Dukey try to help Brain Freezer get a girlfriend.

"King Johnny": Johnny becomes obsessed with domination after Susan and Mary bring his chess pieces to life.

"Johnny Re-Animated": Johnny uses one of his sisters' inventions to bring two cartoon characters Dawg & Bone to the real world in order to scare Sissy out of the house, but the characters mistake Porkbelly for a zombie world and try to destroy it.

"Johnny Cakes": It's Lila's birthday and the family spends the morning to make her birthday a success. Johnny struggles to make her breakfast, Hugh tries to figure out a good but inexpensive gift for her, and the twins keep Lila trapped in her bedroom until Hugh and Johnny are ready.

"Johnny Tube": Johnny wants to become an Internet sensation trying to record a successful video.

"Sleepover at Johnny's": In a parody of The Cat in the Hat,^[16] Johnny is dragged into Susan and Mary's plan to get Gil to be in a sleepover, but Bling-Bling Boy and Dark Vegan's daughter Jillian become involved as well, with usual chaos ensuing.

"Johnny's Got a... Wart!": Johnny gets a wart, and when his sisters try to get rid of it, they unintentionally give the wart intelligence. At first the wart seems to make Johnny's life better, but he tries to take over his body as he gets more powerful.

"Johnny's Royal Flush": When Susan and Mary turn Johnny into a fish as part of one of their experiments, Hugh flushes him down the toilet by mistake where he ends up in the sewer, and he has to swim for his life when he runs into an alligator.

"Johnny Test's Day Off": Johnny ditches school with a relentless truant officer in hot pursuit.

"Johnny and Dark Vegan's Battle Brawl Mania": Dark Vegan once again tries to destroy Johnny, who is trying to cheer up lonely Repto-Slicer.

"A Scholarship for Johnny": Hugh wants to train Johnny to be good at sports so that he can get a sports scholarship for college.

"Johnny Boat Racing": Johnny, his friends, and his enemies all compete in a boat race against an arrogant rowing team.

"Johnny Lock Down": Johnny is determined to get a flytrap plant from his sisters for his school's science fair.

"Good Ol' Johnny Test": Johnny is in charge of the school play about recycling while Susan and Mary create a garbage-eating monster. 

"Johnny X Strikes Back Again!": After taking away the entire lab, the General accidentally creates two mutant super agents that take over the world. It's up to Johnny X and his friends to stop them and save the world.

Note: This was the last episode with Louis Chirillo as Dukey.