Possible Clues:

• Creator of giant peach rider James
• Dahl who wrote 'Charlie and the Chocolate Factory'
• "James and the Giant Peach" author Dahl
• -- Dahl, author of 'Charlie and the Chocolate Factory'
• -- Dahl, children's author and short story writer
• Creator of Willy, the chocolate maker
• & 6 Across Children's author (1916-90), born in Wales
• Man making way round lake
• Wonka creator's first name
• "The Witches" author Dahl