These celebrities look scary in their Halloween outfits for all the wrong reasons. They're not scary in a ghost and ghoul other-worldly kind of way. They're scary because they're clearly insane for thinking these outfits look good.
Typically at Halloween costumes representing monsters and skeletons and witches were worn to scare off demons. You might see sheets with the eyes cut out, skeleton suits and stuff like that. What the celebrities below are wearing aren't “costumes” at all; they're more like outfits worn by z-list porn stars. Or at best, they're more like the clothes these guys wear in the privacy of their own themed dominatrix dungeons.
What's scary is how happy with themselves the celebrities look. Why Mariah thought an angel in lingerie has anything to do with Halloween is anyone's guess. She's clearly on top of the world though and is mentally congratulating herself for using the opportunity (she thinks) to wear her undies in public. Worse still is Coco. Ice-T is (lame) having a laugh, but Coco is striking a serious pose and basically saying with that pout “I'm untouchable I'm so damn hot.” Please.
Someone put a sheet with the eyes cut out over these guys, fast.