The Skull Wyrm (Drakine Friit-Dráki, "Death-Dragon"; also known as the Keeper of the Castle or Xúskedev, "Secret Tower Keeper") is the magically reanimated skeleton of a deceased dragon heavily resembling a Firedrake or Pyrespine, found in northern Ethanol.
The Skull Wyrm is a magically reanimated skeleton, thus, is composed almost entirely of bone with severely decayed ligaments, flesh, and wing membranes lingering, preserved mostly by the extreme cold of its "home". It is approximately 60 feet in length from its snout to its tail, with a wingspan of about 80 feet. The membranes of its wings are decayed and fragile, accounting for the innumerable holes and tears It has a large amount of fractures in its skull, shoulder blades, and right femur, suggesting a violent but prolonged death. Long, sharp spikes run down its vertebrae starting at the base of the head, but these abruptly end between the wings, the remaining length of the skeleton showing evidence of these spikes having been snapped off. Despite the battered and worn appearance of the skeleton as a whole, the dragon's claws and teeth remain very sharp. Its skull is framed by four back-curved horns and an eight-point crown. In terms of build, it resembles a True Firedrake in general body structure, but has the bulk and spiked appearance of a Pyrespine.
The Skull Wyrm appears invulnerable to magical damage, but can still be harmed by blunt force. Its claws and teeth seem unbreakable in general, and the rest of its body appears to be sturdy, even with cracked bones. It has vast wings which, if the membranes weren't decayed, would be able to achieve flight by natural means.
On closer inspection, the Skull Wyrm appears to have a "core" of Mana within its chest cavity, supposedly keeping it animated. It is unknown how this core is maintained, as the Skull Wyrm's master is thought to have died in the Radiant Era.
The Skull Wyrm has little other notable physiology to speak of, being a magically reanimated skeleton rather than a living creature.
The Skull Wyrm appears to possess formidable regenerative qualities, reforming itself quickly after an attack has shattered part of its body or separated two bones from each other.
Despite the torn membranes, the Skull Wyrm can still fly by magical means.
It does not have a venomous bite, but bacteria from rotting flesh (preserved by the cold of the environment) can create a fatal infection in most bite victims that don't die of blood loss first.
Being a mindless creature, the Skull Wyrm is unaffected by Euthoran dracoimpery and dracomancy. Attempts via off-world variants of these abilities have not been reported.
Despite appearing to be a Firedrake or Pyrespine, the Skull Wyrm has no apparent affinity with fire, but is completely resistant to heat and cold.
The Skull Wyrm appears to be sentient and is actively hostile. It will seek out any intruding life and destroy it, often targeting living dragons as well. It has not been observed to speak or make any noise, nor does it appear to need to feed, though it will attack large prey (namely the aforementioned dragons) tear at it with its teeth while the target is still alive, but leaving the dead or dying target when fatal damage has been dealt. The target usually dies on the scene, or escapes and dies several days later of acute infection.
The Skull Wyrm appears to completely disregard its own self-preservation to the point of flying straight into another dragon's fire or a blast of magic from a skilled mage. The only thing it will do to protect itself is use its tattered wings as a shield, or very rarely fly out of the way of an attack. In the rare case that the Skull Wyrm is trapped, it will remain alert but relatively docile, watching its captor intently until any flaw in its imprisonment is spotted. It will then take full advantage of this flaw and attempt to destroy its former captor.
It has been observed to give up pursuit if the intruder leaves the vicinity of the castle before the Skull Wyrm can catch it, but these cases are rare due to the Skull Wyrm's surprising speed when flying and its resilience to the wind and bitter cold which would impede its prey.
The Skull Wyrm is found exclusively in Ethanol. While it is usually flying around the ruins of a castle in the northern, mountainous area, it can sometimes be sighted in the southern half of the continent. These sightings are rare, as it is almost invariably seen soaring around the castle as if patrolling, or resting idle on one of the castle's towers to keep vigil.
The Skull Wyrm was a dragon presumably killed by the harsh elements of northern Ethanol, or perhaps another dragon when fighting for territory or food. It was later found by a sorcerer who had, for unknown purposes, erected a grand castle in the northern mountains. The sorcerer reanimated the skeleton of the dragon as a sort of golem protector, known to local dragons as the Keeper of the Castle, Friit-Dráki, or Xúskedev (the term generally decided by the dragons' spoken language and whether they thought the creature deserved a name). The Skull Wyrm, as it was named later by humans attempting to settle, was designated as a guardian to the castle, keeping locals away, after the sorcerer delivered a warning not to approach. This warning was heeded after the locals discovered the Skull Wyrm would attack all who neared the castle.
At some point many years later, a small figure with proportionally vast wings, its exact form obscured by distance and a blizzard, flew from one of the higher windows of the castle, the Skull Wyrm perched on one of the towers calmly watching it leave. This figure, as well as the sorcerer, was never seen after this occurrence, and it became somewhat of a local legend among the humans who would migrate to the southern coast later.
- When the Phasma was discovered to exist, there were passing theories that the Skull Wyrm was of this species, but it quickly became apparent that the Skull Wyrm was simply animate, not undead, when a necroimperist attempted to control it with a fatal lack of success.