Possible Clues:

• Playwright requires hapless mule with funny-looking basket etc
• Irish author of Waiting for Godot
• Writer's series of holy books current estate regularly discarded
• Playwright who wrote 'We are all born mad. Some remain so'
• Waiting for Godot playwright
• Sat across awkward mule with loop of rope he produced? Happy Days!
• Author of 33 Across (maybe)
• Writer badly mauled (but not dead) getting signal to enter burrow
• 'Waiting for Godot' author