Tributes are flowing for Carlo Bonomi, the actor behind the voice of children's claymation character Pingu, after he died on the weekend at the age of 85.

Remembered for his "noot noot'' phrase, the Italian vocal actor passed away in Milan on August 6 with the cause of his death unknown, publication AF News reports.

Viewers knew Bonomi for his "Penguinese", the language spoken in the stop-motion series Pingu which aired six seasons between 1986 to 2006.

Bonomi was the unscripted voice behind all the show's characters for four seasons, before he was replaced by vocal actors David Sant and Marcello Magni when the show was renewed for seasons five and six.

Pingu is about a young penguin who sometimes gets up to mischief on his family's polar ice cap in Antarctica.

Fans have praised the late actor for his service as a children's entertainer by sharing pictures and videos of Bonomi online.

"RIP Carlo Bonomi, thank you for your service in children's entertainment and for giving my childhood some light to shine in the dark," one fan posted to Twitter.

"May the Noot Noots never fade from our memories."

Meanwhile American cartoonist Travis Bickerstaff said Bonomi's legacy will live on through others.

"If you're wondering if this will be the end of Pingu, it's not," Bickerstaff wrote.

"Other voice actors in the Pingu franchise had carried on Bonomi's legacy, since he established the 'Penguinese' language for the series."

Bonomi was also well-known in Italy as the voice behind the announcements played at Central Station and Florence Santa Maria Novella Station, which were used up until 2008.

He also played a part in a number of Italian shorts, including line animation La Linea, The Line.