Nang-go-sang (The Wolf-Looking-Back Face)

Nang-go-sang uses the characters 狼 (wolf) and 顧 (to look back), literally meaning the shape of a wolf walking and then turning its head to look behind. In physiognomy, it symbolizes a face that possesses a strong tendency to be suspicious of those behind them or to betray others.
The anecdote from ancient China's Three Kingdoms period, where Cao Cao warned against Sima Yi by calling him a "Nang-go-sang," is very famous; this term has since been used as a label for a dangerous individual who could turn their back on the center of power at any moment.
Betrayal, treachery, and the cruelty of a wolf—this is said to be the true countenance of a traitor.