Sleep Arrows

The purple sleep arrows are specifically made by the ranger Tseramed in  Ultima VII.

Description
Besides a modest increase in damage, the tip is made from the stingers of giant bees, giving the  arrow the ability to put the target to sleep. Despite this useful effect however, they are rare, since only Tseramed makes them. He will give the Avatar some for free in Ultima VII.

Effectiveness of the Weapon

 * Tseramed's Arrows add +1 to the weapon's basic points of damage.

King's Savior Arrows
In  Ultima VII Part Two, sleep arrows are created by applying king's savior to any plain arrows. This will create an arrow that is capable of putting any creature to sleep, and is specifically needed to kill Draygan.

Trivia

 * The arrows made by Tseramed only appear in Ultima VII.