How would you indicate to your players that a creature is a minion?

[dave2008]

I don't, to me minions are there to show off how bad-ass the PCs are and how they have progressed.

 

[Imaculata]

Minions are always the first to retreat if the leader falls, and they are also highly dedicated to protecting their leader. So it should be obvious from their combat behavior. I wouldn't explicitly tell my players they are minions though. Instead I let my narration get that feeling across.

For example, I had an evil wizard in my campaign with cultist minions. I decribed to my players how they were covered in self-inflicted scars as a sign of dedication to their faith and leader. When other henchmen fled, the minions stayed with their master, even when the situation looked dire for them. They also dressed differently than any of the other foes.