Kieran Culkin as Fuller McCallister
Fuller is the youngest child in the Frank and Leslie McCallister family and is Kevin's cousin. He had to share a room with Kevin the night before their trip to Paris, which wasn't great news for Kevin because Fuller was notorious for bedwetting, often blamed on his excessive consumption of Pepsi.
As the smallest McCallister kid, Fuller didn't always receive a lot of respect from his siblings and cousins. On the night before their flight to Paris, a brief skirmish around the dining room table nearly resulted in him being squashed by his father. After arriving in Paris, he enjoyed watching "It's a Wonderful Life" in French.
