I executed a repeating command block with the command:
/entitydata @e[type=Skeleton] {Health:1}
It works, but when it tries to attack you it can't, try it and you'll understand me.
MC-103188
Continuously changing a skeleton health turns it crazy.
Resolved
Invalid
0
Any issues caused by changing nbt tags during the lifetime of a mob, will not be fixed as it's unsupported.