Definition of as artful (or clever) as a wagonload (or cartload) of monkeys in English:

as artful (or clever) as a wagonload (or cartload) of monkeys

phrase

British
informal
  • Extremely clever or mischievous:

    ‘plot-wise, it was as mischievous as a wagonload of monkeys’
    • ‘He immediately named his replacement, describing him as: ‘Highly inventive, with a real love for film and as clever as a wagonload of monkeys’.’