What are the derogatory idioms?

Sharp-billed monkey face ―― a thin angular face

Rat thief and dog thief

Flock around like flies or wander around like dogs looking for food/focusing on making profits.

conspire with each other

Can't tell good from bad.

do evil

Despair drives a dog to jump over a wall-a cornered beast will do desperate things.

With thieves

As cruel as a wolf

be ungrateful

cold

be ungrateful

Unwilling to fail in an evil attempt

Regard the enemy as father-regard the enemy as relatives.

Rely on one person and secretly help another.

wreck the country and ruin the people

An incorrigible person

Have ulterior motives/motives

The Walking Dead

Completely isolated

Dictators and traitors of the people