Horrid Henry's Favourite Day is the first episode of Series 2.
It's Be Nice to Your Brother Day and Henry's got the chance to win a Class Zero game if he can be nice to Peter all day.
- When Peter gives Henry thumbs up after he cleans his room, his hand under his glove (which he uses to check for any signs of dirt) seems to be missing, making him resemble Master Hand from the Super Smash Bros. video game series.
- At the beginning of the episode, Henry has no reason to say "Noooo!" after thinking what it would be like to be nice to Peter all day as he doesn't need to do it.