If you don't have a a super speedy, snowball-wielding arm like Buddy the Elf, well this gun is the next best thing.
Taking snowball fights to a new, strangely military level, Mark Rober created a snowball machine gun, and an accompanying video that shows everyone how he made it. The concept starts with a landscaping leaf blower, and ends with a ghostbuster-looking weapon that can fire 13 snowballs in half a second. There's even a trigger that controls the airflow, and a plunger that controls the rate of fire. Check out detailed instructions on how to make one for yourself here.
The rest of the video consists of snowball fight scenes, which this dude obviously dominates. After all, he's just modernized snowball warfare. The snowbank battlefields will never be the same.