Chris Rock says voicing a film character is ''easy'' compared to ''real work''.

The 47-year-old actor lends his voice to the role of Marty the zebra in the 'Madagascar' film franchise and he is grateful about being able to star in computer-animated movies rather than be a cleaner.

He said: ''It's easy compared to work. I mean, we're working right now, but we're not working like the person who's got to clean up this room later. That's real work.''

But David Schwimmer - who portrays Melman the giraffe in the 'Madagascar' movie series - insists he took on the role because he's always loved animated movies rather than because of the financial benefit.

He added: ''I don't think we do it just for the money. We're all fortunate enough to have had a career. For me, I'm such a fan of animated movies and wanted to be a part of a great one. Ever since I was a boy, I loved animals - and in 'The Jungle Book' it was wonderful to see them brought to life.

''I'd never tried it, never voiced a character. When I was offered this, I said, who's my character? They said: 'A giraffe.' And I thought: 'Of course. I have a long face, I'm taller than the other guys.' It was a chance to try something new.''