Wither Skeleton – Official Minecraft Wiki
https://minecraft.gamepedia.com/Wither_Skeleton
Wither Skeletons are immune to regeneration, poison, fire, and the Wither effect. Despite their immunity to fire, they still seek shade or water during daylight if they are in the Overworld . They sink in water, do not swim and do not drown like other Undead Mobs.
DA: 99 PA: 5 MOZ Rank: 47