white elephant
noun
- a possession that is useless or troublesome, especially one that is expensive to maintain or difficult to dispose of（保管起来费钱又费事而又难以处理的）累赘东西, 费而不惠的东西。
词源
from the story that the kings of Siam gave such animals as a gift to courtiers considered obnoxious， in order to ruin the recipient by the great expense incurred in maintaining the animal.