Are you looking for a Biblical Costume?  Here's a great idea!  Why not go to your party or trick-or-treating as a Cardinal?  Represent the Catholic Church!

Can costumes and religion mix?  Sure, why not?  It's not like you are dressing up like the Cardinal and carrying a pitch fork.. well, maybe you are, but I don't need to know about that.  ;)

The Cardinal Costume above comes with a  Long White under robe with Gold metallic trim and detachable clerical collar, deep Red velvet over tunic, two detachable neck stole pieces with metallic trim and matching mitre hat. Do note though.. the Cross is not included.

So put a smile on your guests, family, friends or neighbors faces.  Shock them a little.. even make them think about some things they might not that usually very unholy day.

What you might want to know about Cardinals before you decide to play that part:

If you're curious, the Cardinal is a senior ecclesiastical official of the Catholic Church.  Often this is the Bishop.  And Cardinals are actually collectively thought of or referred to as the College of Cardinals.  And this is the body that actually elects the Pope!  If there is a death or resignation, they are charged with the duty to fill the vacancy.

They do a variety of other things as well including counseling the pope when he needs it.

Now Cardinal Bishops are actually the most senior prelates of the Catholic Church.  They are the most plentiful.  Note also that most Cardinals are Bishops.

The Cardinal Priests you find as part of the three orders of Cardinals in Catholic Church.  They actually rank above the Cardinal Deacons and below the Cardinal Bishops.

Cardinal Deacons are the lowest rank three orders of Cardinals the Catholic Church.

Then you have your Lay Cardinals... these are the Cardinals that aren't actually ordained as Deacons are Priests and may have very basic duties; only those who are already priests or bishops can be appointed Cardinals.

Also Reference:

• What is a Cardinal? 
• College of Cardinals 
• Cardinal: Definition