Possible Clues:

• Hopper's earliest form? Piece in American bar
• One who grows up, then eventually croaks
• Swimmer thanks head of diplomatic staff
• Staff supporting little swimmer in pool
• Swimmer hoping to develop into jumper
• Little European pond-dweller
• Frog's larval stage
• Young beast bit German neighbour
• Splash and support little swimmer
• Larva with gills