Sonic 3's Jim Carrey got so into playing the new role of Robotnik's grandfather Gerald that he helped "design the prosthetics": "No detail was too small"
Despite previously saying he would need a "golden script" to return to acting, Jim Carrey is pulling double duty as both Doctor Robotnik and his grandfather Gerald Robotnik in the upcoming Sonic 3 – even going as far as helping design the elder Robotnik's prosthetics.