If the Animated Skeleton is killed they cannot be brought back by any form of resurrection. As punishment for receiving a second life through dark magic the gods seize the skeletons soul and chain it in the afterlife.

Your ability scores each increase by 1.

Skeletons do not feel the affects of aging.

Animated Sleletons vary widely in height and build, from barely 4 feet to well over 8 feet tall. Regardless of your position in that range, your size is Medium. 

Your base walking speed is 30 feet.

You can speak, read, and write Common and one extra language of your choice. Skeletons speak the languages they spoke in life.

You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.

If damage reduces the animated skeleton to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is bludgeoning or from a critical hit. On a success, the animated skeleton drops to 1 hit point instead.

An animated skeleton can burrow as an action by dismantling its bones and shaking them into the ground, while underground the skeleton is immune to all affects. The movement speed is reduced to 10 feet while underground. In order to return to the surface another action must be taken.

Animated Skeletons are immune to poison, exhaustion and cannot be put to sleep even through magical means.

Animated Skeletons are feared by the common people and hunted by guards and heroes, they must wear a disguise in towns. Animated Skeletons are proficient in intimidation.

Animated Skeletons only need 4 hours for a long rest and 30 minutes for a short rest. This is to restore the necromantic energy holding them together and keeping their soul intact. While resting a skeleton is a pile of bones but can see and hear normally.

Animated Skeletons are dark creatures the gods have forsaken. Due to the dark origins of the skeleton they cannot receive healing from divine sources such as healing spells from Clerics, Paladins. They instead receive damage from those sources.