Sarah Snook Grace (voice) Kodi Smit-McPhee Gilbert (voice) Jacki Weaver Pinky (voice) Magda Szubanski Ruth Appleby (voice) Dominique Pinon Percy Pudel (voice) Tony Armstrong Ken (voice) Paul Capsis Ian / Narelle (voice) Eric Bana James the Magistrate (voice) Davey Thompson Ben Appleby (voice) Nick Cave Bill Clarke (voice) Adam Elliot Denise Floyd (voice) Luke Elliot Headmaster / Security Guard (voice) Jub Clerc Nursing Home Resident Mavis / Sperm Nurse (voice) Flynn Wandin Additional Kids Voices (voice) Andy Wright Additional Adult Voices (voice)