Skeletal Wyvern

Skeletal Wyvern (Draconis Ossis) are very dangerous monsters which can drop Granite legs, and the rare Draconic visage. Level 72 Slayer is required to kill them. An Elemental shield or mind shield must be equipped when fighting them. They are the lowest leveled monster that drops the Draconic Visage.

Strengths and Weaknesses
The player must equip an Elemental shield or mind shield whilst fighting these or he/she will be hit for very significant damage (50+). Black D'Hide armour or better with barrows gloves (RFD) together with an amulet of glory or Fury amulet is recommended. Players can also use the Protect from Magic prayer to lower the max hit of the Ice breath attack, but it is not as effective as any of the shields. Wyverns attack with either melee or range. They also possess a freezing-breath mage attack similar to dragon breath, but which can also sometimes freeze players in a fashion similar to the Ancient Magicks ice barrage spell. They have high Defence, high Attack and high Hitpoints making them very challenging opponents. They also require 72 Slayer to kill.

Using protect from melee Prayer and Prayer potions is recommended as they hit fairly high and regularly. Players can still take damage from the freezing-breath attack but much less overall damage results when you prayer protect from melee. Because of the elemental/mind shield requirement, ranging attacks are only possible with one-handed weapons. On the defense, note that when wyverns jump up and emit a blue glow then they are about to make a ranged attack. Players can then momentarily switch to the protect from ranged prayer and only suffer damage from the ice breath mage attack.

It is worthwhile to first attack a wyvern with a p++ type weapon, inflict a poisoned wound, and then revert to your preferred attack weapon and style. It seems that skeletal wyverns have a weakness to slashing attacks and there is a significant increase in the frequency of successful hits when the player's effective attack rating is 100 or more. It also has been reported that there is a safe place close to the entrance where one can range or mage a wyvern on the other side of the entrance with impunity.

It should be noted that despite being skeletal creatures they are not classified as undead. As such wyverns are not vulnerable to the effects of the Salve Amulet. Note as well that they are not classed as dragons either, so that the Fist of Guthix Dragon Slayer Gloves do not give bonuses when fighting them and the anti-fire potion has no effect on the wyvern's ice breath attack.

Locations
Asgarnian Ice Caves

Drops
There is much commentary on the paucity of decent drops from an NPC that is such a difficult and expensive kill. Charms are dropped approximately 50% of the time, albeit two charms are then always dropped. Gold pieces or nothing, besides the bones (which are each worth 50 prayer xp), forms the usual loot.

100% drop: Wyvern bones
 * 12 Runite bolts
 * 7-26 Adamant bolts
 * Mithril bolts
 * Adamant crossbow (u)
 * 30, 44, 132 or 220 Coins
 * 30 Air runes
 * 30 Water runes
 * 10 Chaos runes
 * 3 Law runes
 * 7 Blood runes
 * Chaos talisman
 * Cosmic talisman
 * Super Attack Potion (1),defence potion(3)
 * 10 or 11 Soul runes
 * 60 noted Pure essence
 * Earth battlestaff
 * Gem
 * Herbs
 * Black axe, Adamant axe
 * Snakeskin chaps
 * Dragon Dagger (P+) (rare)
 * Granite legs
 * Draconic visage (very rare)
 * 2 Charms (Crimson are very common)
 * Clue scroll (level 3)
 * Shield left half (dragon)
 * lobster
 * Bass
 * Mithril sword, black sword
 * Limpwurt seed, Jangerberry seed