Skeletal Dragon

Skeletal Dragon (骨の竜) is a powerful undead being that mimics the shape of a dragon.

Appearance
The Skeletal Dragon is composed of countless human bones with an overall height up to three meters tall. Formed from bones with a rib cage devoid of organs nor flesh, the Skeletal Dragon appears light despite its large frame. Its head contains four hollow eye sockets, each with a crimson glow. The jaw of the skull is lined with sharp teeth along with a pair of bat-like wings attached to its shoulders and four limbs.

Abilities
Aside from its massive strength, the Skeletal Dragon has the capacity to fly like any other dragons out there. This dragon's specialty relies on its unique ability that nullifies any magic that ranges up to 6th tier. Therefore, this dragon's ability makes it the worst opponent for some magic casters. Particularly, the low-level magic casters who used spells lower than the 7th-tier are the ones helpless against it. The injured Skeletal Dragon can heal off of magic spells that supplied negative energy as shown with how Khajiit supporting it.

In the Web Novel, Skeletal Dragons had the abilities of skeletons. The Skeletal Dragon’s body was constituted from bones, hence it could negate any damage from piercing weapons. However, it was considered weaker than vampires.

Trivia

 * In the Web Novel, the Skeletal Dragon's difficulty rank is estimated to be at 48. Khajiit spent two months performing a ritual to summon a Skeletal Dragon.
 * Skeletal Dragons are apparently, common around at the Katze Plains. In the Web Novel, at the Katze Plain, it was formed from the bony remains of a hundred people, a body that is contaminated by the essence of death.
 * Narberal Gamma destroyed two Skeletal Dragons created by Khajiit with a 7th tier lightning spell.
 * When Narberal Gamma limited herself to Nabe's level and easily damaged a Skeletal Dragon, Khajiit thought she was either a Mithril or Orichalcum adventurer.
 * From Nabe and Khajiit's battle, we can extrapolate that Platinum ranked adventurers are the minimum level needed to defeat them.
 * The strongest magic caster in the New World could only cast spells up to the 6th tier, making everyone think that the Skeletal Dragon has an absolute resistance against magic.
 * Skeletal Dragon's magic invalidation ability bears a close resemblance to Ainz's magic invalidation ability as both their powers nullified damage below 6th tier spells.