Skeleton

A skeleton is a hostile creature that wanders on the surface at night. It spawns every night in graveyards (one from each gravestone) and always spawns from monster portals. A skeleton alone is weak; however, it tends to attack in groups, making them a hassle to destroy. All kinds of skeletons are present in all worlds but the Underground World.

A skeleton will attack the nearest shelter it will encounter. It does not drown, that is, it does not lose health underwater. It cannot climb in walls like dwarf, but it can jump heights of one block. It can fall from heights of ten blocks without losing health.

Nocturnal
Skeletons only attack during the night. When the sun rises, they try to escape from sunlight, returning to the portal or to the graveyard, depending where they came from. They are not destroyed by the sun and do not burn at the sunlight like zombies. They simply become unable to attack and cannot be attacked when hit by the sun.

If they managed though to penetrate the shelter - specially underground shelters - so that the sun light can not hit them at the morning, they will remain aggressive, trying to find their way out. If there is not enough stairs for them (at least one at each two blocks), they will stay in there chasing the dwarfs.

Shield stair
If a path is blocked by a two-block (or more) high cliff during the night, a skeleton will tend to do a defending stance, making them not able to attack, but providing a stepping stone for other mobs to proceed. Multiple skeletons with their shields up can stack on top of each other, possibly negating defensive ditches or moats intended to defend a players stockpile. They do not cripple when not hit by sunlight.

The melee skeleton is the only skeleton able to form this stair. The called Skeleton with Shield won't perform this strategy.

Not only all types of monster can jump on the shield, but also dwarfs. But on the dwarf side it's not a naturally occuring behavior, because dwarfs will either attack or flee from skeletons, as they see them (depending on the dwarfs' health and other few factors). And if the skeleton is attacked by a dwarf, it will move, disrupting the stair formation. By direct-controling a dwarf, it's possible to make them jump on the shields without disturbing the skeletons' formation.

Farm
All sort of skeletons spawn from gravestones every night, making them able to be farmed by the player. They tend to drop quite a variety of items (see their respective infobox). They can providy very basic armor on early game, and can be a considerable source of iron on late game.

It's easy to farm them without efforts since the Advanced Construction tech is attained. One to three (depending on the level's difficulty) well placed pets will deal with the every night waves of skeletons and zombies.

Appearance
Skeletons are usually equipped with a crude sword or a steel mace as weaponry and a buckler as a shield, a right boot equipped and a shoulder pad on the left shoulder. Some spawn with yellowish white color on their eye sockets and some spawn with a portion of their head cracked off. As skeletons hit a door/hatch made of iron or steel, their weapons tend to make a clink sound. When crippled, the color on their eyes vanishes and their body just fall.

Even though skeletons have a steel mace equipped, it does not have the same damage as the mace a dwarf would craft in a forge.