If it is a family gathering and you are part of the family, try to show up and be with the family, then duck out and be Santa, then get out of costume and return to theparty with as minimum fuss as possible.
Mr. MEAD: Well, the thing is, you have to remember that I'm, you know, I'm the mummy that cooked the dinner, and I'm the one that planned the owl party, and I'm the one making the ice cream treats, so the costume's got to be on the simple side.