The characters combine to mean “the wild heart of a wolf cub,” powerfully conveying the idea of an individual with an inherent and unchangeable predatory nature.
The term 狼子野心 originates from the ancient Chinese historical text, the Zuo Zhuan (《左传》). In a famous story, a minister warns his lord not to promote an official's son, stating, “This one is a wolf cub; you can't raise him. He has a wild heart” (狼子野心…是乃狼也，不可畜). The warning was ignored, and the son later instigated a rebellion, proving his treacherous nature was indeed innate. This idiom is deeply rooted in a cultural view where the wolf is an overwhelmingly negative symbol of treachery and cruelty. This contrasts with some Western cultures where wolves can also symbolize freedom, nobility, or pack loyalty. A useful Western comparison is the phrase “a wolf in sheep's clothing.” Both describe a dangerous, hidden nature. However, “a wolf in sheep's clothing” focuses on the deception of a harmless exterior. In contrast, 狼子野心 focuses on the person's innate, unchangeable, savage essence. It's less about the disguise and more about the fundamental, untamable wildness within, which will inevitably reveal itself. It's the core belief behind the fable “The Scorpion and the Frog,” where the scorpion's betrayal is simply its nature.
狼子野心 is a very strong, formal, and exclusively negative term. You would use it to make a serious accusation about someone's dangerous and treacherous character.