Arrow/Bolt of Frost

Theres arrows have been enchanted with the power of Evocation Magic. While simple, the craftsmanship and runework are notable and elegant.
These arrows are sold individually for 80 GP and the magic within each arrow is lost after it is fired.

When fired from a bow or crossbow, the shaft magically splits into 5 separate beams of energy which then hurl towards enemies within range.
Each beam can target the same creature or another one within range. 

Make a ranged weapon attack for each beam. On a hit, a target takes 3d6 cold damage for each beam that strikes it. 
Additionally, a creature hit by one or more beams must make a DC15 CON Save or have its movement speed reduced by half for 1 minute.