This Wither Skeleton Tweaks Mod is a great mod for Minecraft. It changes the way that Wither Skeletons behave in game, and does not change any other aspects of the game at all. The Wither Skeleton Tweaks Mod can be configured to suit your needs, which will help you enjoy this mod even more!
This mod adds a new drop type item when killing Wither Skeleton which is Wither Skull Fragment, these 9 pieces when combined will give out Wither Skeleton Skull.
All Skeleton born in the Nether now will 100% be Wither Skeleton (Minecraft Vanilla will spawn both regular Skeleton and Wither Skeleton).