BATMAN ‘66 #16
It's “Egghead Unbound” as Batman's most egg-centric foe returns to terrorize Gotham City. Frustrated by his repeated defeats at the hands of the Caped Crusader, he invents a device that will egg-celerate his brain development to that of a being from the 40th century. Is this really possible? Does he now possess super-human abilities? Or has his mind simply gotten scrambled?