River Song's sonic trowel

River Song used a sonic trowel to stun King Hydroflax's warrior monk bodyguards, though it was ineffective against Hydroflax's robot body. The Twelfth Doctor considered the trowel "just embarrassing" and gave River a sonic screwdriver of her own. (TV: The Husbands of River Song) River later used her trowel during her adventure in a Mesopotamian excavation site in 1924. (AUDIO: The Boundless Sea)