a visible sign of evil intentions or evidence that reveals a person's true villainous nature

to be cocky

to leave a task unfinished or leave behind unresolved issues

will not last long; used to describe a person or situation whose days are numbered

to delay finishing a task or leave loose ends behind

to adopt a humble or cautious attitude after being intimidated, defeated, or placed in a humiliating situation

pig's tail (meat)

to have one's tail between one's legs

(coll.) a person who puts on an act, such as feigning ignorance, pretending to be solicitous, or acting innocent

lit. rat's tail; fig. a follower of inferior stature