Outside the House of Humor on El Camino.  There are two of these Killer Klown things either side of the store front.  This place is a one stop shop for costumes and whatever and they keep up with every, and I mean every, event that might require costuming or props of some kind.  A few weeks ago it was Burning Man, then Oktoberfest, you get the idea.  Always a fun place to check out or even just walk past.