a wolf-like child will have an evil heart—aggressive designs; wild (/sinister)ambition; vicious scheme; wolf-hearted; wolfish nature
❍ ～，非是，莫丧羊舌氏矣。(《左传·昭二十八年》)A wolfish child will have a wild heart. None but he will destroy the clan of Yangshe.
❍ 谚曰： “～。” (《左传·宣四年》) There’s the common saying，“A wolf like child will have an evil heart.”/操曰： “吾素知吕布～，诚难久养。” (《三国演义》151)“I know Lu Bu quite well，” said Cao. “He is a wolf with a savage heart.and it will be hard to feed him for long…”/我们就在谈判桌上跟它斗，向全世界人民揭露它的～； …… (杨佩瑾《剑》71) …We must struggle against them on the negotiating table—exposing their aggressive designs before the world’s people.
❍ ～难料，看跋扈渐肆咆哮，挟势辜恩更堪恼？ (洪昇《长生殿》) Who can judge the ambition of the wolf cub丨That starts to snarl and glories in its power，丨Forgetting the gratitude it owes?/可笑玄宗不觉其～，却要信他是真心，好不痴心。(鲁迅《中国小说史略》111) The emperor failed to perceive the reprobate’s ambition and believed him to be sincere; the very height of folly!
狼子野心
wolf cub with a savage heart;wolfish nature with wild ambitions; aggressive designs of the wolves; vicious and ambitious design
狼子野心lánɡ zǐ yě xīn
狼子：狼崽子。狼崽子虽小，但有凶恶的本性。比喻凶恶、残暴的人本性难改，有狂妄的欲望和狠毒的用心。wild ambitions, the aggressive designs of the wolves