According to THR Bailee Madison (The Bridge to Terabithia) has signed to join Holmes, and Guy Pearce is in the final stages of negotiations.
Madison will play the girl who discovers the creatures and is fascinated by them until they prove dangerous. Pearce (if signed) will play her father, an author frustrated by his daughter’s tales of monsters who will not believe her even though his girlfriend (Holmes) backs her up about the little beasties.
Del Toro and Matthew Robbins wrote the script with Troy Nixey directing. The movie is set to begin production next month in Melbourne, Australia, close to where the master of horror is shooting The Hobbit.