In The Office Season 2 episode, Christmas Party, the office originally plays Secret Santa, but when Michael is unhappy with the gift Phyllis gives him (a homemade oven mitt), he changes the game to Yankee Swap.
Jim: What is Yankee Swap.
Michael: One person chooses a gift. The next person can either choose a gift or steal that person’s gift. If your gift gets stolen, then you can steal someone else’s gift or choose a new gift.
Jim: I thought that was called Nasty Christmas.
Pam: Yeah, we call it White Elephant.
Here’s the sequence of events.