Celebrating Christmas in a park + white elephant gift exchange

We'll sit in a park and listen to Christmas songs while eating Christmas cookies.
I encourage you to come wearing silly Christmas themed clothing. There might be a prize for the best dressed person.

The main event will be a white elephant gift exchange.
What is that?
Everybody brings one wrapped gift (value around 5-10€) and puts it in a pile in the middle.
One person picks a gift to open. The next person can now choose to also open a new gift, or to steal a previously opened gift from someone. If a gift has been stolen 3 times, the person holding it will keep it.
In the end everyone walks home with 1 gift.

I'll also bring some Christmas decoration but I'm not sure about bringing a Christmas tree. Trees are heavy. Maybe we'll just decorate a random one in the park.

What to bring: wrapped gift (around 5-10€) and ideally some Christmas clothing (if you don't have anything we might use you as the Christmas tree).
Optional: cookies or other fitting food/drinks