Dahl's book focuses on three blundering farmers -- Boggis, Bunce and Bean -- who decide to exterminate the title character. In fairness, Mr. Fox has been eating their chickens, but the farmers go overboard and Mr. Fox is forced to use his wits to survive.
Clooney would voice the titular Mr. Fox, with Blanchett as his wife.
Anderson and Noah Baumbach wrote the script, which is set up at 20th Century Fox, with Fox Animation entrusted with bringing the story to life.
Clooney is currently directing and co-starring in the football drama "Leatherheads." The "Syriana" star has "Ocean's Thirteen" and "Michael Clayton" due for release this year.