Legend has it that there is a kind of eel, which is relatively rare. It likes to eat dead dogs, dead cats and carrion. Its body is stout and its shape is not obviously different from that of ordinary eels. When the moon is round and bright, it often swims out of the cave and looks up at the moon. This eel is called full moon eel, which is highly toxic and inedible, and will die if eaten.

There are many legends about "full moon eel", but they are all the same. The most famous one is the story skillfully solved by Ji Xiaolan. The general content of the story is that a peasant woman, without knowing it, cooked for her husband with a full-moon eel fished out of her grave, and her husband died.

The peasant woman who was thought to have poisoned her husband cried on purpose, which aroused Ji Xiaolan's suspicion. Ji Xiaolan accidentally saw the record of full-moon eel in a medical book, so he ordered people to catch hundreds of eels and skillfully separate the only full-moon eel. After being slaughtered and fed to the dog, the dog suddenly died. This grievance is also over.

The above contents refer to Baidu Encyclopedia-Full Moon Eel.