Possible Clues:

• Irritable boating enthusiast?
• Kenneth Grahame character
• Irritable (colloq.)
• Nameless tyrant can become irritable
• Get annoyed when lunatic swaps bishop for rook
• Cross — character in 'The Wind in the Willows'
• The worse for wear, e.g.
• Irritable underground associate of mole?
• One abstaining enters light cross
• Despicable