After Walter takes up origami as a martial art, Dennis scoffs and comes up with his own martial art, and so the two prepare to battle it out.
Inspired by the mayor's call to make Beanotown Green-o-town, Dennis tries renewable fuel sources to launch his space mission.
Dennis uses curtains as a giant sail, not knowing its specially for the kitchen and loses it to the Colonel.
In attempt to keep cool on a hot day, Dennis' gang dig their own pool in Dennis's backyard.
Dennis comes across a bundle of objects that inspire him to be a private investigator and begins searching for Gran's lost teapot.
Dennis goes to the fair with his friends and Bea, but the owners of the fair of spoiling their fun due to last years events, especially the bouncy castle operator.
Dennis' gang decide to make their own alien film. When Walter stumbles across them filming, he's convinced there is an alien invasion and raises a red alert in Beanotown.
The joke shop owner, Mr Har Har, needs Dennis's help to persuade his mother not to close the joke shop down. The gang decides to try and pass Mr Har Har off as a successful vet.
With one backstage pass for a Ratbucket gig, Dennis and his friends pass themselves off as Ratbucket, only for the real Ratbucket not to be able to play at his own concert.
Dad takes Dennis to his school reunion party, in an attempt to teach him to behave grownup, but it doesn't go as planned when Walter's dad renews his rivalry with Dad.
Visiting Gran in hospital, Dennis disguises Gnasher as a baby to evade detection, but Gnasher is taken away by the short-sighted Mr and Mrs Butcher.
Dennis tries to help Dad get a raise, but Dad ends up fired, so Dennis makes Scrimp's office seem incapable without Dad.
The police chief hires a super-efficient cop called Boot to replace Slipper, who tolerates no act of mischief. Teamed with Walter, Dennis tries to get Slipper back on the job.
Dennis hatches a plan to bail Gnipper imprisoned in Beanotown dog pound, by impersonating a misbehaving dog.
Dad agrees to buy Dennis the best skateboard there is if he can win a prize at the upcoming school award ceremony. The only prize that Dennis can try to win is the best behaviour prize, so he does everything he can to win the contest.
After a bet from Walter on the Dance Contest, Dennis trains Pie Face to be a dancer. Meanwhile, Dennis' dad tries to cure Gnasher of his fleas.
In an attempt to reclaim the park, Dennis and friends try to scare everyone with a 'pond monster.'
Dennis tries to get a birthday present by saying thank you to his relatives. However, because of Dennis' naughty personality, they take his attempts in a negative way.
Dennis and friends have a go at catching the Legendary Beanotown Pike, but when Walter hears about it, the game is on.
Mum is going to the yoga school and leaves Dad in charge. During her absence, Dennis, Curly and Pie Face try to make a pie, with disasterous results to follow.
To get his friends back from Walter's group, Dennis challenges Walter to a videogames battle.
After a wrestling accident, Gnasher swallows a canister of laughing gas at the vet's. Dennis, along with Gnasher hide in the conference centre, where dad gives a speech. However, the canister leaks, causing Gnasher to fart laughing gas and having everyone laughing.
For a school project, Dennis and Walter both build robots. However, during an accident, both robots merge, causing Dennis and Walter to defend the school.
During a camping holiday, Dennis, Gnasher and Dad meet Terry Tuff and get challenged to a nature survivor's challenge, ending with a race to the summit of Mount Beano.
Dennis and Co. have to control Pie Face's obsession with pies during the Pie Festival. Otherwise, they will be grounded.
To win a football match against Dennis' team, Walter fattens Gnasher up and brings in top striker David Peckham. But will this stop Dennis and team from winning?
On a school trip, Dennis finds out that he is descentant to a warrior tribe. He also discovers that Montanna Smith (a famous Indiana Jones-esque explorer and one of Walter's personal heroes) is actually a thief who's trying to steal the treasure of Dennis' ancestor. Will he be stopped before he gets his hands on the treasure?
Athena gets Gnasher envy when seeing a pampered version of Gnasher in a magazine and when she hears that Dennis owns an Abyssinian wire-haired tripe hound (Gnasher), she wants him. However, being an owner to Gnasher isn't all cracked up to be!
Dennis tries to get a first aid badge to get into a wrestling match. However, Walter's the judge and it's not going to be easy.
Dennis is made to attend a Neighbourhood Watch meeting by his parents. This, however clashes with a jam session with Curly and Pie Face.
Dennis breaks Bea's toy horse, so Dennis is searching for a new one to cheer her up.
Dennis is grounded on the first day of the summer holidays, but Dennis doesn't manage to stomach it. But the town isn't having him sneaking out of home.
Gnasher and Gnipper enter a dog show, regardless of Walter saying they don't have true talent. He wants Athena and Miss Mini Wuff to win, but Walter has just underestimated Gnasher's true capabilities.
To have Dennis be kind to him, Walter disguises as fortune teller Madam Gigi to warn Dennis that if Walter gets hurt, he "will get his just dessert."
There's a new computer system which keeps data for the school which works using a memory stick. This gives Dennis an idea, but it makes Walter suspicious.
Gran's hurt her foot after trying to build a pigsty for her pet pig, Harley. She makes Dennis deal with Harley and then starts living in Dennis' tree house and Dennis isn't happy about it!
Walter applies for work experience at Scrimp Towers, where Dennis' dad works. Dennis tries to help dad with the work and save his job from Walter after an accident.
Dad gets promoted, which means his new job will involve his family moving to Drainotown, much to Dennis' disappointment, so he tries to change dad's mind and stay in Beanotown.
Dennis plays a prank on the citizens of Beanotown, causing them to evacuate, which causes trouble for Dennis later.
Dennis gets a new amplifier but doesn't have a chance to try it out because of Bea's demands and threats to let off a lethal fart if not done so he decides to hide the beans. However, Bea retaliates by stealing the volume knob off the amplifier.
To avoid getting into trouble, Dennis acts ill, leading him into a boring night in the hospital.
Dennis builds a BMX track near Athena's VIP party. However, Athena is standing for none of it.
Dennis gets a case of the hiccups from Mr. Har Har's can-o-giggles and is looking for a way to cure them ready for a film premier.
Dennis' parents hire Nanny Moonbeam, a hippy who has an unusual and peaceful way of curing Dennis' bad behaviour. However, it gets on his nerves and eventually drives his parents up the wall.
Dennis tries to please mum by behaving for the whole day. But this isn't easy for him.
Dennis and Gnasher are on a mission to find Walter's pet rabbit after Gnasher scares it away.
The garden is accidentaly wrecked when Dennis tries to give Gnasher a bath, so the gang have to fix the mess before Mum comes home.
After hearing reports about a bat creature in Beanotown, Dennis highly suspects that The Colonel is a vampire.
Curly doesn't attend band practice and Dennis finds out that this is because of a plan by Walter to sabotage the Dinmakers, involving a collectible series.
An accident happens at school and Mrs Creecher says that she will tell Dennis' parents about it at the school parent's evening. Dennis, Curly and Pie Face set up a scheme to stop this from happening.
Dennis, his friends and Walter's friends get marooned on a desert island when Dennis attempts to escape a boring field trip.
Dennis makes a line of practical jokes for Mr. Scrimp, called 'The Menace Collection.' However, Dennis soon learns that it will put Mr. Har Har out of business.
