If you are going as, say, Diana Ross you look pretty silly if you are blonde and pale.
Dressing up as mass murderers? Don't get that.
Of course I was always the one at the office Halloween party in my business clothes. When someone asked what my costume was I would hand them a business card that said "IRS" and say, "I would like to talk to you about your deductions".
Got voted most scary costume twice.
I went to such a party once in a suit, as I hated costumes. I said I was a plaintiff’s lawyer there to sue someone. No one talked to me.