The Dark Judges - Judge Death, Judge Fire, Judge Fear, and Judge Mortis.
Once human, but turned into supernatural creatures by the Sisters of Death. They decided that all life was a crime and murdered everyone on their world before invading other dimensions and exterminating life there.
The Dark Judges are the arch-enemy of Judge Dredd and appear in 2000ad and the Megazine.
Judge Fear had the ability to literally scare people to death by opening his mask and showing victims his face.