Eureka!

Henry's Eureka! moment

Eureka! is a moment that occurs whenever Horrid Henry gets an idea for what to do in different situations. It is followed by 'That's it!', making it into 'Eureka! That's it!'.

Appearances

Series 1

• Horrid Henry's Hike - Because Henry wants to go home to watch Rapper Zapper, he has to go to the lake sooner.
• Moody Margaret Moves In - Henry has an idea to make his duty easier when Margaret's snooping in his stuff in his room.
• Horrid Henry's School Fair - Henry wants the Double Drencher in the school fair to spray all his enemies.
• Horrid Henry Tricks and Treats - Henry comes up with a plan to trick everyone during their Halloween as being dressed as a Dark Avenger to enjoy his.
• Horrid Henry's Sports Day - Henry decides to throw sweets at every other racer for them to eat so he can win the 400 Meter race.
• Horrid Henry and the Bogey Babysitter - Henry knows Rabid Rebecca is scared of spiders, so he puts them to scare her.
• Horrid Henry and the Demon Dinner Lady - Henry decides to refill lunchboxes to stuff Greasy Greta up and force her to go to the School Dinners room.
• Horrid Henry Goes Swimming - Henry tells Andrew about the latest news about the shark. By telling him, he swims out of the pool.
• Horrid Henry Goes to Work - Henry decides to photocopy Bill's bottom after he gets tired of photocopying these documents.
• Horrid Henry Gets Rich Quick - Henry wants to have more money by selling items and Peter as a slave.
• Horrid Henry's Holiday - Henry tries to trick every camper by destroying their picnics.
• Horrid Henry's Perfect Day - Henry decides to be good because good children go to the fair like Perfect Peter.
• Horrid Henry: Happy Birthday Peter! - Henry can make a clown not escape after his countdown has elapsed by putting the key in the magical hat.
• Horrid Henry's Time Capsule - Henry has a plan to get Bunny back: dig for the time capsule and bring it to Peter.
• Horrid Henry Runs Away - Henry plans to run away from home.
• Horrid Henry's Underpants - Henry cannot handle with Great Aunt Greta's underpants, so he looks in the lost and found cupboard to look for a pair of underpants.
• Horrid Henry Makes Some Money - Henry can use the Fangmangler book to tell the Best Boys Club the story about a Fangmangler.
• Horrid Henry's Dance Class - Henry wants to do karate by borrowing Ralph's karate costume.
• Horrid Henry Where's Fluffy? - Henry tells Peter what to do and how to get Fluffy back from Margaret's treehouse.
• Horrid Henry's Fairy Dance - Henry has an idea to get Peter in trouble; fairies.
• Horrid Henry Reads a Book - Henry tries to win the reading contest by logging in more reports in his book report.

Series 2

• Horrid Henry's Favourite Day - Henry doesn't have to be good to Peter.
• Horrid Henry and the Alien Invasion - Henry knows that water can defeat the aliens.
• Horrid Henry and the Lost Dog - Henry wants to get Basher out of the house by going outside of it.
• Horrid Henry and the Name Game - Henry can use the phone to name the black cat.
• Horrid Henry Happy Birthday Steve! - Because Henry said if only if it wasn't happening at the same time as the final, he would invite Rich Aunt Ruby and Stuck-Up Steve for tea.
• Perfect Peter Pumps Up - Henry takes Bunny to make fun of Peter. Meanwhile, at school, he gives Bill it to make sure that Peter is pumping up.
• Horrid Henry and the Gross DVD - When Henry wants to see Gross Class Zero, he goes into the clubhouse and has to vote on whether or not the club members want to watch it.
• Horrid Henry and the Green Machine - Henry can catch up with watching Gross Class Zero, play race tracks, and toast some bread for breakfast since the Windo-matic 5000 can produce their own electricity.
• Horrid Henry's Petsitting Service - Henry decides to make a pet sitting service so that he can earn more money.
• Horrid Henry on TV - Henry can help himself if he can't get Margaret to help him.
• Horrid Henry's Haircut - Henry decides to take the perfect haircut as he was putting on a fake hairstyle so that he doesn't behave like a baby.
• Horrid Henry Changes a Nappy - Henry talks to Margaret and Susan that he can change a nappy.
• Horrid Henry Takes a Shortcut - Henry and Ralph can use the trolley from the supermarket to win the cross-country race.
• Horrid Henry and the Antiques Rogue Show - Henry knew that anyone can sign an autograph.
• Horrid Henry and the Killer Boy Rats - Henry knows that if Bert dunno, the Killer Boy Rats won't see him.

Series 3

• 

  Horrid Henry, Rockstar! - Henry decides to write a letter to Ed Banger.
• Horrid Henry and the Perfect Plane - Henry can ask Mike to trade his comic for Mike's plane when he sees it in the store, and he couldn't get one since he had no pocket money.
• Horrid Henry and the Booger Bogey - Henry can try to steal Peter's Bogusem Beetlearius so he can prove that he's the king of the booger bogies.
• Horrid Henry: Aliens Ate My Homework - Henry puts cereal on Peter's head after he says, 'Aliens saved the day!'. Mum knew the cereal box was empty, so the aliens must have eaten them all.
• Horrid Henry's Unhappy Day - Henry goes to his room after he picks up the phone so he can call the Gross Class Publishers for another copy of this week's Gross Class Zero comic.
• Horrid Henry, Rocking the World - Henry wants to show confidence by copying Fang's movements.
• Horrid Henry, Nothing But The Truth - This time, Peter says it. He comes up with an idea to write a book about all the horrid things Henry's done.
• Horrid Henry Delivers The Milk - Henry has an idea to go the other direction around in a circle when Evil Eddy Edwards was ahead of them delivering the milk.

Series 4

• Horrid Henry Knows It All - Henry saw Brian beside him, and he knows it's Brainy Brian.
• Horrid Henry and the Single Sock Saga - Henry decides to wash everything in the laundry machine so that they all smell the same.
• Horrid Henry Gives It All Away - Henry doesn't need his toys for a very long time, so he decides to give them all away and replace them with new ones.
• Horrid Henry and the Purple Pass - Henry called Bert a genius since Henry and his friends know that they're at the next stop.
• Horrid Henry Helps Out - Henry decides to write a letter to Big Bob.
• Horrid Henry Gets the Gig - Henry's gig is tomorrow afternoon, but he has detention with Mr Soggington tomorrow afternoon. So, he has a goldfish book that Mr Soggington loves to leave detention early.
• Horrid Henry and the Number Gnomes Knowhow - Henry wanted to borrow Peter's Number Gnome for the maths test.

Series 5

• Horrid Henry's Uber Homework - Henry knew that homework can be an app for it.
• Horrid Henry: King Henry the Ninth - Henry decides to block the bathroom's entrance by using a string.
• Horrid Henry and the Awful Author - To make Peter stop crying, Henry says to him it's not his fault.

Other appearances

There is only one occasion where Peter says this catchphrase too. This only appearance is in Horrid Henry, Nothing But The Truth, when Peter writes a story of all the things Henry has done after being so cross.