Every Saturday through Christmas, kids (and their pets, too!) are invited to stop by the Union Square Petco to meet St. Nick. This isn't your typical mall Santa, though: All proceeds from photographs will be donated to the Petco Foundation's Tree of Hope campaign, benefitting local animal welfare groups. Plus, on December 8 families and their furry friends can attend a Holiday Pawty featuring treats, prizes for Best Dressed and onsite adoptions by the Long Island Bulldog Rescue. All ages.