Instagram user Dimati rides off to the SantaCon festivities via the subway with his elf sidekick.
Santas get rowdy, especially the ones with candy cane canes.
Mashable's own Taylor Casti took part in the SantaCon festivities.
Here's a reindeer and a NYPD cop hanging out at Tompkins Square Park.
The Ev Grieve local East Village blog writes that the NYPD got the "SantaCon memo."
Santas plus man with a dark beard run through Tompkins Square Park to start the bar crawl in New York City.
SantaCon participants drinking beers inside a bar in New York's East Village.
It's time for some SantaCon grooving.
Instagram user Fundamentals said "Tonight we took over the streets of London."
SantaCon crowds stormed the streets of central London.
Drinking outside of Saint Paul's Cathedral in central London isn't the most pious thing to do.
Open bottle wine drinking in front of Saint Paul's Cathedral in London.
Reindeer, Santa and Chicken share a drink at London's SantaCon.
Time for a group shot of boozing -- these gals united for a pic in central London.
An artsy shot by Instagram user Stepyuk of the London SantaCon crowds.
Thousands participated in the annual SantaCon tradition of drinking and dressing up in Christmas-inspired costumes Saturday for a day-long pub crawl in New York.
SantaCon takes place in more than 300 cities around the world, including New York, London, San Francisco, Vancouver and Zurich.
See also: In Scrooge Move, NYPD Doesn't Want Bars to Serve SantaCon This Year
In New York, this year's alcohol-fueled procession of revelers dressed as Mr. and Mrs. Claus will be heavily patrolled by the NYPD due to past reports of the merriment turning into vomiting, urinating and fighting on the streets.
Those dressed as Santa Claus must remove fake beards to be served alcohol, and no alcoholic beverages will be permitted on Metro-North and Long Island Rail Road transportation, according to the New York Daily News.
With the London SantaCon taking place ahead of New York because of time-zone differences, Facebook videos of the festivities have already begun to show up on SantaCon London's Facebook page.
Here's a recap of SantaCon's international updates via Twitter.
Out at #Santacon #Santarchy today - enjoying it! http://t.co/cxzO8wFZ9A
— Kieran ✪ Strange (@KieranStrange) December 14, 2013
What #Santacon left behind at the steps of All Souls Church #London. Litter and broken glass everywhere pic.twitter.com/MucbBqvyhB
— Philippa Thomas (@PhilippaNews) December 14, 2013
It is 12noon. Alcohol is banned from @LIRR & @MetroNorth trains/stations through noon tomorrow to maintain orderly travel during #SantaCon.
— MTA (@MTA) December 14, 2013
UPDATE: the rivers of puke continue to flow through lower Manhattan for #SantaCon http://t.co/6NScu2aORF
— Gothamist (@Gothamist) December 14, 2013
Santa's having a jolly snowball fight! Come join the fun! #NYCSantacon
— santacon (@santacon) December 14, 2013
Have something to add to this story? Share it in the comments.
Image: Kena Betancur/Getty Images