Possible Clues:

• Mount high in the Holy City
• Animal at last trained: a wild animal
• Booth charge for horse
• Horse no-one backed after delay
• Adult male horse
• Stud of high standing in holy city
• That's the last, beastly, feline - no, equine - king
• The tall one with your boy around sounds hoarse
• He was the last great cat to sound hoarse
• Horse no one backs after delay