Arf was the nickname given to a K-9 series droid owned by Havet Storm. Little more than a toy Arf was given to Havet by his grandfather Morvet Storm. A Jedi, Morvet used the droid to record a secret audio message for his grandson, telling him of his potential to become a Jedi and warning him of the dangers of revealing his abilities to others.
Morvet Storm also hid within the K-9 a lightsaber, which remained hidden inside Arf until Havet Storm received the droid and activated Morvet's secure message by touching a DNA sample reader located on the droid's casing.
Arf proved to be invaluable to Havet Storm on a number of occasions, who kept the droid with him at all times, hidden within a large pocket in his bulky coat. The droid was extremely loyal, responding only to his master's voice and the two formed a close bond.