Stray Skeletons when killed by a player occasionally drop an Arrow of Slowness. However when killed by a tamed wolf the Stray will never drop an Arrow of Slowness. This is surprising since wolf kills get the player experience and all other mob drops (including Bows, Armor etc).

To recreate:
1. Find a Stray Skeleton
2. Tame a wolf
3. Observe that when Stray Skeleton is killed by wolf no Slowness Arrows drop.