Are you trying to decide which character from the "Harry Potter" series that you would like to dress as for Halloween? If you want to dress up as pure, crazy evil, a Bellatrix Lestrange costume is perfect for you. Lestrange is arguably the most unhinged of all Voldemort's Death Eaters, so you're going to need a fair amount of "crazy" in order to pull off the perfect Bellatrix Lestrange costume.
Find a black wig, if you don't already have long, dark hair. Before Bellatrix Lestrange entered Azkaban, she was a tall, dark beauty, but the prison did a number on her physical appearance as well as her mental stability, so streak the wig with gray paint.
Paint the hollows of your checks with black or gray face paint to make your face appear more gaunt. You can also add dark circles under your eyes. Put a thick layer of black eyeliner around your eyes and paint your lips dark red.
Get an old black dress from either the back of your closet or a thrift store. Cut holes and slits in it to make it look more worn. Don't forget to add shoes to the costume. Try using a pair of knee-high, high-heeled boots.
Make a wand out of a piece of paper, double-sided tape and glue. Stick double-sided tape diagonally across a piece of paper, roll the paper into the tape, put glue on the free corner of the paper and roll it tightly until it's dry. Or, you can make it easier on yourself and just use a stick you find outside.
Convince someone else to dress up as one of Bellatrix's companions. One of your girlfriends could dress as Bellatrix's sister Narcissa Malfoy or one of your guy friends could be "The Dark Lord" himself.
Memorize some of Bellatrix Lestrange's favorite spells. She wasn't afraid to use an "Unforgivable Curse" and she was especially fond of the "Cruciatus Curse." Yell "Cruciatus" a couple of times and your costume will be complete.