The Elf Copter is a Hardmode, post-Plantera enemy that appears during the Frost Moon event. It travels through blocks, firing bullets rapidly at the player if it has a line of sight.

Defeating an Elf Copter rewards 8 points ( 16 points ) during the Frost Moon event.[2]

It is referred to as "Elf Helicopter" in the wave counter.

The Bestiary "The elves aren't just flying toy helicopters, these are fully combat ready. All that inventing finally paid off!"

Desktop 1.2.3.1 projectiles are fired slower and do less damage.