From their announcement:
The VFM Christmas Elf Troop Special is here! Special includes Santa’s Veteran Elf Troop Half Squad, his eyes on the ground F.O. with snowman observation post, and gift giving MG team. Also get the tank killing, bunker busting Santa himself with a Bazooka FREE! Find the Special in Specials Section of the Victory Store as well as finding other Elf Troops in the Storybook Wars Section.