Wolf in sheep's clothing
One day, a wolf decided to disguise himself. He put on a sheepskin, disguised himself as a sheep, and sneaked into the flock. He thought that this would not only avoid the hunter's pursuit, but also facilitate the predation.
He lowered his head and pretended to eat grass, hiding from the shepherd's eyes. When night fell, the wolf who had been locked in the sheepfold by the shepherd was about to start enjoying his food. The shepherd opened the sheepfold and planned to kill a sheep to make dinner for himself. He chose the sheep disguised by the wolf, grabbed him, and killed him with one swing of his knife.
[Meaning of a wolf in sheep's clothing]
The evil doer often comes to harm through his own deceit.