Aw, Chicken Run is one of my favourite movies! For the feet, I would start with a base shoe and cover it with the form, using foam fabric, for example. Good luck and don't forget to post photos!
Working on: Astrid (HTTYD) Toothiana modern human versión (ROTG) Secret cosplay
Future cosplays: Astrid's Heather costume (ROB)Anna (Frozen)