Children SEE them as kung fu heroes, and parents use them to lure their children to eat breakfast cereals - these four green fighting machines revolutionised the comic book industry and spawned a billion-dollar franchise.
They are the Teenage Mutant Ninja Turtles, and their latest venture, TMNT, is a movie animated by Hong Kong studio Imagi. A series of action figures and accessories will be released along with the film.
'What it [the Ninja Turtles] did was give legitimacy to the comic book industry in that a huge franchise could come out of comic books, even independent comics,' said director Kevin Munroe, a veteran animator.
'They did 3,000 copies of that first issue [of the comicTeenage Mutant Ninja Turtles], and they did it for US$8,000. The franchise has made like US$6 billion, which is phenomenal.'
Turtles creators Kevin Eastman and Peter Laird self-published the first issue of the comic series 23 years ago. The story revolved around four mutant turtles - each specialised in a different weapon - battling against a villainous ninja master and his evil clan in New York City.
The comic book gradually grew into a lucrative franchise thanks to its popular children's merchandise - from breakfast cereals to toothpaste, and stationery to video games - and a popular cartoon series on TV.
The success of the Turtles encouraged many amateur artists to self-publish, creating a new wave of independent comics. Merchandisers and licensing agents meanwhile set their sights on making gold out of the black-and-white comic pages.