It's Halloween and Horrid Henry prepares to go out trick or treating with Mum and Perfect Peter, who is dressed up as a bunny rabbit. Henry cuts his hair to make him scary and Mum grounds him. However, Henry has a plan; he tricks his Dad and sneaks out into the night, scaring kids from his school and stealing their treats. But the real challenge is Moody Margaret.

While her parents are on holiday, Moody Margaret bunks in with Horrid Henry. However, only a single minute is enough trouble for Henry when having his arch-nemesis in the same house and/or room with him, so he decides to use his spectacular thinking to devise a plan and get Margaret kicked out.

After Perfect Peter loses a tooth and earns a pound from the Tooth Fairy, Horrid Henry grows extremely jealous over the fact that everyone he knows except him has lost a tooth. He decides to trick the Tooth Fairy into giving him a pound. Will he be successful?

It's another ordinary day for Horrid Henry, until he notices one thing: Mr. Kill is missing. Using his detective skills, Henry looks around his house and interrogates people who supposedly have the need for revenge against Henry for all of the bad deeds Henry has committed to them. With no progress, Henry decides to talk with the one person who could possibly have a good revenge against him: Perfect Peter.

Horrid Henry is taken to work by Dad and meets his boss' son, Bossy Bill, and he has to do everything he says or else. However, all Bill does is manipulate Henry into committing terrible acts which end up ruining the company's workplace. So, Henry decides to get back at Bill by tricking him into doing the worst possible thing at work, and secretly on camera for his father to see

Mum is organizing the school fair and is on the hunt for old games and toys. Henry and Peter’s old games and toys, to be precise. Henry generously donates his Walkie-Talkie-Burpy-Slurpy-Teasy-Weasy Doll – in fact he’s glad to see the back of her. A little careful research and he’s located the mega prize in the Treasure Map too – oh, life is sweet. Or is it?

Horrid Henry hates sports day. He never wins at a single event. So he is not happy when sports day arrives, and he must compete. However, there is a way for him to win this year, and that is if he cheats...

Just when Henry is settling down for a day of TV, his parents drag him out on a dreadful hike, much to his dislike. But eventully he finds out a way to hurry them home, which involves letting a bull loose...

When Stuck-Up Steve comes to stay for Christmas, Horrid Henry decides to make sure Santa Claus gives him the right presents...

Horrid Henry has always had a way of sending any babysitters trying to look after him refuse to look after him again. But when Rabid Rebecca, the toughest teen in town, who every child is afraid of, comes to babysit him, it seems Henry has finally met his match.Henry discovers that his usual tactics just don't work, and he's forced to be even more inventive by teaming up with his brother Perfect Peter.

After spending some time eating school dinners, Horrid Henry is happy to be going back to having Packed Lunches for dinner time at school. But when he goes back to the Packed Lunch room for the first time in a while, he meets his new enemy - Greasy Greta, the Demon Dinner Lady. She uses the rule of 'No Sweets In School', by eating any sweets the children brought in their packed lunches. The only way to stop her is by playing her at her own game...

Every year, Horrid Henry's birthday parties are a nightmare for his parents. They always say they will never let him have another party, but they always give Henry another chance the following year. This year, Henry wants to go to laser zap, but he is banned for the trouble he caused there. His party is held at home, but it has games which Henry hates like 'Pass the Parcel'. Then Henry decides to use his new present - his Super Soaker 2000 Water Blaster - to make things a little more interesting...

All of the children are collecting Gizmos out of cereal boxes. Gizmos come in different colours. The rarest on e is gold. For a while, none of the children have a gold Gizmo, but eventually, Perfect Peter gets one, and Horrid Henry tries everything he can to get his hands on it...

Henry's home made time machine takes Peter back to the future, to visit the Peter Museum. Peter is delighted, he always knew he was special. But even he doesn't realise quite how special, until Moody Margaret brings him back to the present with a bump.

Horrid Henry's class go for swimming lessons at the local swimming pool. Henry, unfortunately, isn't good at swimming, so he is not at all pleased to go. Later, at the pool, he decides to play a horrid trick on all the good swimmers, by telling them there's a shark in the pool...