Possible Clues:

• College study incorporating Republican symbol on coat of arms
• Legendary animal makes RC union wobble
• Nuncio upset about rook: unreal creature
• Place to learn mawkishness, a thing of legend
• Fabulous animal that's product of agricultural college?
• Start-up worth a billion dollars, in a modern coinage
• Mythical beast makes RC union shaky
• A ____ represents Scotland in the UK’s royal coat of arms
• Mythical creature, fabulous bird, displayed over in a French home
• Legendary creature in college -- something afoot!