As businesses close for the holidays and the week slows down in the ease up to Christmas, Boston Dynamics created a … strange, promotional video for their Big Dog robots.

Three of the four-legged robots show off their weird but effective traversal of grassy lawn as they pull Santa’s sleigh. May not be appropriate for people who thought the Big Dog was creepy in its other video appearances, because this one is … something else.

Boston Dynamics markets their robots to the U.S. military, and some of their projects were funded DARPA. Their robots include Big Dog, the humanoid Atlas, LittleDog, and the Cheetah, which can run up to 29 miles per hour.  The BigDog can carry a load of 340 pounds and walk on a variety of terrains. (We’re not sure how heavy the sleigh in the video is, but the robot does seem to be pulled it along, the bottom of the sleigh hidden by cloth.)

BigDog can run up to 4 miles per hour and climb slopes up to 35 degrees, some of which which is tested around the campus of Boston Dynamics.