Possible Clues:

• To go up and down in here will never get you to the top
• Last one Puck made an ass of?
• Undersurface
• Source of low comedy in a dream of Shakespeare
• Bed that had a 25
• 'By the sound of it, to tease in the base boom (6)'
• Lowest of the low
• Fool's position in form at school
• Worst role for actor in Shakespearean comedy
• Shakespeare character, ass perhaps