Harley Bird, the teenage voice actor behind cartoon character Peppa Pig, has stepped down after 13 years in the role. Eighteen-year-old Bird, who has voiced 185 episodes of the programme and won a Bafta in 2011, said that her time on the hugely successful children’s series had been “the start of an incredible journey”, adding that her colleagues had given her “unforgettable memories”.

The teenager from Rochdale, Greater Manchester, was the third person to voice TV’s most famous anthropomorphic pig, following Lily Snowden-Fine and Cecily Bloom. She will be succeeded by nine-year-old Amelie Bea Smith, whose agent said she had been a “huge fan of the show since she was little” and that it was a “dream come true”.

Neville Astley and Mark Baker, the British animators behind the show, said they were delighted that Smith was joining the team, as well as citing the strong legacy of the previous Peppa voice actors, including Bird, whom they described as “a key part of the success of Peppa Pig”. Bird reportedly earned £1,000 an hour for her role, and also recorded songs for the Peppa Pig album, which became a viral hit after its release last July.

Bird was a ‘key part of the success’ of the show, voicing the character for 185 episodes ... the Peppa Pig family. Photograph: Five

Originally rejected by the BBC, Peppa Pig has become one of the most recognisable and lucrative children’s cartoon franchises in the world since it debuted on Channel 5 in 2004. Airing in 118 territories, the Peppa brand also garners huge sales of merchandise across the globe, notably in the US and China, with the character’s trademark pink, skewwhiff face found on merchandise from baking sets to jewellery. Last August, toy giant Hasbro purchased the Canadian company that owns the rights to the show, Entertainment One, for $3.3bn. In October, Merlin Entertainments, owner of Legoland and Alton Towers, opened a Shanghai attraction, joining an existing Texas park. There are also plans to open in New York and Beijing. Peppa Pig World in Hampshire opened in 2011.