Halloween is a 'holiday' that is used as an excuse to get and give free candy.
In addition, the theme often revolves around scary things such as ghosts, spirits, darkness, and death.
My mother, being a highly religious Christian, is against all that Halloween stands for.
Also, since Christmas wasn't really proven to be Jesus' birthday, we don't do Christmas. And neither does she let us do birthdays.
This actually is really bothersome for me, seeing as I used to celebrate Christmas and birthdays with my extended family and friends. But I only really did stuff for Halloween once or twice, but since I was so young I never really ended up getting to do much. My overprotective parents never let me go trick-or-treating, "like all the other kids."