A leghorn is a breed of which farm bird?

Which word means both a leg joint of meat and to pawn something? What is a legal document that transfers ownership of land called? According to a legend, which British king was seen in 1788 having a conversation with an oak tree? Which name belongs to both a legendary city of gold and a Cadillac model discontinued in 2002? A lepidopterist studies which insects? Which Leslie Nielsen film comedy series was based on the TV show "Police Squad!"? Which ruthless Russian ruled as tsar from 1547 to 1584? Complete the title of Marcus Pfister's picture book about sharing: "The Rainbow ___".