Possible Clues:

• Full of gumption
• Lively one kept in iron pen
• Brave — irritable
• Finally take in hand young becoming quarrelsome
• Showing courage
• Spirited eccentric bites first
• Lively, fit? Yes, for a change
• Tough and spirited
• It's key to Yeti's movement that's easily excitable
• Spirited and fit? Yes, possibly