There are 100s of costumes from full get ups to just a mask. And some of the best involve simply just their weapon. I personally believe that the Santa Claus killer is one of the best, it is literally a Santa Claus outfit. Adolph Theodore, who was known as the Santa killer was a guy who dressed up as Santa for parties and even the mall. One of the most famous stories on how he killed is about when he had been dressed in a Santa Claus costume opened fire at a crowded nightclub in Istanbul during the 2017 New Year’s celebrations, killing at least 39 people and wounding close to 70 others. Idk about you but I think that having a guy be an entertainment at a party you’re at, and him shooting up the place is so scary.

Edward John Louis Paisnel Is another one that I think is the best. Be is known as the beast jersey killer. He wore a rubber mask that looks like his face is melting, and nail-studded bracelets. He worked as a fisherman and they said they were a little sus of him because he was so good at cutting them open in like the exact way to kill them right away. He would go into peoples houses at night and attack women and kids.