The creditor clung to him like a lamprey, refusing to let go.

lamprey 是一种原始的无颌鱼类，俗称"七鳃鳗"或"吸血鱼"。这个词来自拉丁语 lampreda，指这种鱼会吸附在其他鱼类身上吸食血液的特性。在句中用作比喻，形容债主像吸血鱼一样紧缠不放、难以摆脱。