Christmas 2019 is another Event where players are required to collect a said item (in this case, puppies) and return to the first story location (Rodger Family Home) to collect the rewards.
Each story location, starting with Snowman Park thru Abandoned Toy Storage, has 5 puppies that you return to the House of Rodger Family. You need to perform certain tasks in most mines to get the puppies released to you.
The Devilla's list & the Rodgers comments to track down the puppies are the clues to go to map page & begin clearing the other mines. Players can either go back to the House of Rodger Family each time 5 puppies have been collected or wait until all have been rescued.