What wonderful idioms do you know?

Tigers, tigers and rivers. Every time I see this idiom, I think of "the tiger violently attacks the hippo". The tiger beat the hippo violently. In fact, it reads like H incarnation, which is related to tigers, but has nothing to do with hippos. It is to fight the tiger with bare hands and cross the river barefoot (without tools). Metaphor is that people are brave and have no plans. It was first published in The Analects of Confucius.