Heart of jackal and fox
Jackal: a kind of beast. It refers to the ferocious, cunning and ruthless heart of a wolf or fox.
interpretation
Jackal: a beast of prey. Of a cruel, cunning, heartless heart like a jackal or fox
source
According to the Dunhuang Bianwen collection, Wu Zixu Bianwen: "when I heard that the king of Chu had no way, I sent out the heart of the fox and killed my concubine."
Examples
His heart is just like that
words whose meaning is similar
Wolf ambition, jackal
usage
To be formal; to be an object; to be derogatory
Heart of jackal and fox
old in age but vigorous in mind - fà duǎn xīn cháng