Possible Clues:

• Word from the Greek for 'walking on tiptoe'
• Trapeze artist, for one
• Tumbler -- a member of the rook family? Not quite: another flying creature
• What would you do without mug and a tumbler!
• Tumbler's performance involving wild boar
• A chap holding mug and tumbler
• Trapezist, e.g
• Boat car (anag.)
• A European gets stuffed by British athlete
• A Balkan kidnapping bishop — one taking a tumble?