Bestiary/Wyvern

The Wyvern is a small poisonous dragon. Its bite carries Deadly poison, which makes it much more dangerous than its size suggests.

Overview

In-game name: a wyvern
Corpse: a wyvern corpse
Behavior: it attacks the nearest target it sees and fights in melee.
Target switching: it re-picks its target whenever it moves, so it may switch to whoever is closest.

Each time its melee attack hits, there's a 50% chance it also poisons the target with Deadly poison.

Deadly poison deals 12.5% of your current hit points (at least 7, at most 26) every 4 seconds, for up to 10 ticks.
Cure it with a cure potion, the Cure or Arch Cure spell, or a healer's bandages and the Healing skill. Higher levels are harder to cure.

Poison immunity: it is immune to poison up to Deadly (Lesser, Regular, Greater, Deadly). Only stronger poison affects it.

Every wyvern carries:

Gold: about 90–225 in total (from its "Average" and "Meager" loot)
1 magic scroll from circles 4–7. With Necromancy enabled on New Bradford, necromancy scrolls can show up too.

It may also carry:

A magic weapon, armor piece or shield (up to 5 chances, from about 5% down to 0.2% each)
A musical instrument (about 0.5% or less)
A level 2 treasure map (1% chance)

Use a blade on the corpse to get:

The Deceit brazier: double-clicking it from within 2 tiles summons one creature picked at random from a list of about 90, and this is one of them. The brazier warns players who step next to it ("Heed this warning well, and use this brazier at your own peril"). It works once every 15 minutes and places the creature within 5 tiles. The summoned creature is set to attack the closest target, even if it would normally leave you alone, and it stays within 5 tiles of the brazier.