Zombies get reinforcements, so why shouldn't skeletons?
With this simple pack installed skeletons spawn two more skeletons within 18 blocks from you as a reinforcement when killed.
Warning: I wouldn't recommmend using this in any world with a mob farm where a player kills skeletons.
Doesn't effect bogged, parched, stray, or other skeleton variant.
Only triggers when a player kills a skeleton. Natural damage to a skeleton ex. lava, fall damage does not trigger reinforcement.
Doesn't really work in caves.

