[32] Novel Entertainment had a dedicated page to the in-universe show "Gross Class Zero" on their website, hinting that a spin-off TV series was in the works.

[35] On 23 July 2007, CPLG appointed Blues Clothing to produce a range a line of nightwear and underwear.

New tracks including My Song, Born To Be Rude, Wanna Be Me and Too Cool For School featured on the Vue Cinema special and will be released on the album.

[42] The game: Horrid Henry: Missions of Mischief, was released for the Nintendo DS and Wii on 4 December 2009.

On 25 November 2011, Asylum and Koch Media subsidiary Europress released Horrid Henry: The Good, The Bad and the Bugly for the Nintendo 3DS.

[45] On 21 January 2022, P2 Entertainment released Horrid Henry's Krazy Karts for the Nintendo Switch eShop.

[48][49] The show starred Steven Butler and Steven Tagg as Horrid Henry, Stephen McGill as Horrid Henry Too, Rachael Swift as Moody Margaret, Alex Tregear as Perfect Peter, Philip Bosworth as Dad, Miss Battle-Axe, Miss Thumper and Ed Banger; Ruth Calkin as Rabid Rebecca, Clark Devlin as Weepy William, Howie McCullough as Aerobic Al, and Katy Porrett as Sour Susan.

CITV in the UK, RTÉ in Ireland and ZDF in Germany acquired the rights to the series in the respective countries.

[64] By March, the series was pre-sold to Disney Channel in France, RÚV in Iceland, SVT in Sweden, NRK in Norway and YLE in Finland, with broadcast deals in South Africa, Turkey and Portugal being negotiated.

[22] In October 2008, the broadcast rights for the three regions were pre-sold to MNet, Digiturk and RTP respectively, in addition to a Polish deal with Op Art.

[66] In the United States, it aired on PBJ and was available for streaming on Netflix until 2023, it was also on Amazon Prime Video,[67][68] and is currently available to watch on The Roku Channel.

In 2014, Cartoon Network and Boomerang acquired the series for Australia, New Zealand, Pakistan, India, South-East Asia, South Korea and Taiwan.

[71] In Wales, the series was dubbed in Welsh and aired on children's block "Stwnsh" on S4C and was titled "Henri Helynt".

The series featured a variety of fun and games, as well as short stories narrated by the title character.