How to craft it
as a weapon it is a stopgap
It drops hard as it flies, so anything past a short lob is a miss, and you aim by arcing rather than pointing. The appeal is entirely supply: one block of snow becomes a pile of these, and a fresh character who spawned near the cold biome can arm themselves in about a minute. The moment you find a real bow it stops being a weapon.
the second life as ammo
The reason to keep a stack is the cannon and the wired launcher. Hooked to a circuit, a launcher gives you an automated defense that costs nothing but snow, which makes it one of the cheapest base traps in the game to run forever. Stockpile before you strip the biome for building material, since hauling snow back later is the tedious part.