A part of the Wickless Remains who have shaped themselves into lowly foot soldiers. They collect the remains of those they slay to add to their own, and they'll pick a fight with you to get it. Even though I am without wax, I've still been the target of many Wickless hasslings.
Strengthstone is effective on units with Slay affixes because, in order to benefit from as many Slay triggers as possible, you must make sure that the unit scores the Slay, which is further guaranteed by having as high an Attack value as possible.
Frenzystone is effective on units with Slay for the same reason Strengthstone is effective. Multistrike has the added bonus of the possibility of scoring two Slay triggers in one wave, because each strike could hypothetically score a Slay.