FOR USE IN SCHOOLS AND LIBRARIES ONLY. When 12-year-old Nate Twitchell takes care of an gigantic egg laid by one of his hens, he is shocked to find that it hatches into a triceratops.FOR USE IN SCHOOLS AND LIBRARIES ONLY. When 12-year-old Nate Twitchell takes care of an gigantic egg laid by one of his hens, he is shocked to find that it hatches into a triceratops.