三番五次 again and again, time and again,
over and over again
害群之马 a black sheep
引狼入室 invite a wolf into the house
open the door to an enemy
狼吞虎咽 wolf down, gobble up
马马虎虎 careless, casual,
not very good, so-so, not so bad, just passable
遍体鳞伤 be covered all over with cuts and bruises
be beaten black and blue, be a mass of bruises