Skeleton

The skeleton is a hostile mob found in Survival, Infdev and  Indev. Skeletons are spawned randomly in new Survival maps and follow players when approached, much like zombies. In Indev mode, they only spawn in dark areas, such as unlit areas on the surface  at night, or in unlit caves.

Skeletons are vastly different in Survival mode than in InDev and InfDev. Both variations can, however, attack other hostile mobs (of the same or different type).

In Survival, skeletons are similar to zombies. They take 4-6 hits to kill and can wear NPC armour, although the armour does not give them any  additional hit points. They inflict 2 hearts of damage upon attack. Skeletons will fire arrows at you and, upon death, will burst out arrows that the player can collect. Killing said skeleton will net you 120 points. One important note about skeletons is that they can shoot arrows through water with little to no effect on speed and accuracy. Therefore, it is extremely hard to kill a skeleton in water, it is best to fight skeletons on land.

In Indev and Infdev, skeletons are fairly fast-paced enemies that will shoot arrows at the player at a decent speed. Unlike the skeletons in Survival mode, InDev and InfDev ones do not currently wear armour. If touched by sunlight (the sun at a 15 degree angle or greater) InDev and InfDev  skeletons will begin to take burn damage until death.

After the Halloween Update, skeletons now hold a bow in their hands.

Mounted variant
Seeecret Friday Update 8 added the ability for skeletons to ride spiders. When a spider is spawned it has a 1 in 100 chance of having a skeleton spawn with it, riding on its back. They are separate enemies though and have separate health bars. This "Spider jockey" has both the ranged arrow attack of a skeleton and the mobility of a spider as well as larger combined health.

Drops
Survival: Alpha:
 * arrows are shot in all direction upon death. Can be picked up and reused.
 * 120 points
 * 0-2 arrows