>Skeletons can now multitask.
They walk, strafe, and shoot at the same time now.
>Thunder and lightning is now 0.02% more scary.
There is a 0.02% chance that skeletal mounts will spawn during a thunderstorm. Approaching them makes them summon a small cavalry of 3-4 mounted and armored skeletons, depending on difficulty.
This also means that if you dismount a skeleton via death, you can then steal their super awesome bone horse the same way you tame normal horses.
Additionally, during thunderstorms, skeletons with armor riding skeleton horses can spawn.
Y'know, as if skeletons weren't already annoying enough before you get a bow.
EDIT x4: Picture I found on reddit.