Minecraft wiki entry for Wither_Skeleton, associated text: Some wither skeletons may have the capacity to pick up dropped gear in normal or hard difficulties. The chance depends on regional difficulty, with up to 55% of them capable of picking up swords higher than stone tier plus any armor. Wither skeletons never take bows; in Java Edition, if they hold a bow (which can be done with /summon wither_skeleton ~ ~ ~ {HandItems:[{id:bow,Count:1b}]}) they shoot flaming arrows even if their bows are unenchanted. They cannot use crossbows.