Bianca Castafiore

Who is she? She bills herself as one of the best opera singers of her generation, despite the fact she only seems to know one song and can't even sing that very well.

Who we'd cast: George Clooney. Just because we want to hear him talk in a high-pitched haughty voice.

Back-up: Cate Blanchett

Tintin

Who is he? Ginger-quiffed kid adventurer.

Who we'd cast: Sam Worthington. It seems to be a new Hollywood law that Worthington has to appear in every major effects franchise, and this is the only place we can fit him. Well, we suppose he could play Snowy.

Back-up: Kodi Smit-McPhee