Show (one's) horns phrase
The devil is typically depicted with horns.
To display one's wicked, bad, or malevolent character.
I have never thought that a nice guy like John could be so wicked until he showed his horns by beating his girlfriend brutally.
I asked my girlfriend wether she still loved me if I had showed my horns.
After showing his horns, he was ostracized by his colleagues.
The verb "show" must be conjugated according to its tense.
The origin of this phrase is not clear.
To be thankful or grateful for one's good luck usually while avoiding a bad situation
You should count your lucky stars as you managed to avoid that violent car accident.