The 1-year-old Puli, an Internet celebrity in his own right (he has 570,000 Facebook fans), wore his shaggy Hungarian sheepdog hair pinned up over his eyes.
Check out the photo of Beast and Chan in her wedding dress:
Priscilla Chan Wedding Dress
Beast first joined Chan and Zuckerberg in their Palo Alto, Calif., house last year, a month after he was born. He has since pooped on Zuckerberg's rug, visited the Facebook offices, and met the Dog Whisperer, Cesar Millan, among other milestones.
Most of all, he has become an important and meaningful member of the family.
Both Zuckerberg and Chan, known as Dad and Mom on Beast's page, feature their beloved dog in the cover photos of their personal Facebook pages.
Walking mom down the aisle to marry dad? Doesn't get better than that.
