1. Balaenoptera musculus   horse   whale   rhinoceros   rat   Hint Half-n-half Clue   2. Camelus dromedarius   rhinoceros   dog   camel   fox   Half-n-half Clue   3. Bos taurus   leopard   cow   horse   frog   Half-n-half Clue   4. Giraffa camelopardalis   fox   lion   giraffe   tiger   Half-n-half Clue   5. Equus caballus   zebra   giraffe   horse   elephant   Half-n-half Clue   6. Elephas maximus   elephant   horse   rhinoceros   dog   Half-n-half Clue   7. Panthera leo   cat   wolf   lion   giraffe   Half-n-half Clue