Hilarious video of what this dog did when wearing Santa pants. In the video description, the owner writes:

It was christmas day so I threw a pair of santa pants on my dog. He was fine walking around but when he ran down the stairs to greet someone, something amazing happened.

This YouTube video has gone viral. It was uploaded on December 26, 2011, and the current hit count, as of today December 29th, is 2,096,376.

Enjoy!