beat a dead tiger—pose as brave; lick sb who is already down ❍ 我以为 “～”者，装怯作勇，颇含滑稽，虽然不免有卑怯之嫌，却怯得令人可爱。(鲁迅《论“费厄泼赖”应该缓行》) I find those who pose as brave by beating dead tigers rather amusing. They may be cowards,but in an engaging way.
打死老虎da si lao hu
flog a dead tiger—attack or criticize those who are no longer in power