5. Robert Rodriguez Performed The Voice Of That Talking Shark - The Adventures of Sharkboy and Lavagirl 3-D (2005)
http://www.youtube.com/watch?v=hhGSeFrYSyo One of the eternal mysteries tied to modern movie-making is that of Robert Rodriguez's constantly irritating decisions to make children's movies, as opposed to, you know, Sin City 2. Granted, Rodriguez has stated on a number of occassions that he likes making movies for his own kids, and that would be kind of admirable, should they ever be any good. Which - let's be honest - they never really are. So imagine the shock when "the director of From Dusk Till Dawn and Sin City" announced that he was making a movie about two characters called Sharkboy and Lavagirl - and in 3-D, no less! Blerg. Anyhow, Rodriguez makes an uncredited cameo at the beginning of the flick, where he takes on the duties of voicing an actual shark. Whereas his buddy Quentin Tarantino is "all about filmography," Rodriguez seems more than happy to load his own canon with middling kids' flicks. And, um, voicing sharks (which, to be fair, is territory which even the likes of Martin Scorsese has ventured into on occassion).