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.

"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.

"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.

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

"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.

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

"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.

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

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

"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 The sisters and Johnny try to find outdated technology to power the tea house.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 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.

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

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

"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".

"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.

"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.

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

"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.

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

"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.

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

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

"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.