Here in Norway we use: "Quisling".
Vidkun Quisling was pretty much Hitler’s voice here in Norway during WW2, he betrayed the country and worked with Hitler when he invaded Norway. After the war he was executed.
So basically the question is do you have a name of a person or something that you use instead of just Traitor or Judas

And I’m not just talking about something you and your friends understand, but when you say it everybody knows what it means.